Best Crate for a 1970?

[JimC]

Folks,

The wife and I would like to purchase a crate motor for our 1970 vert project. We bought the car w/o engine so no rebuild possible. Car was originaly supplied with auto trans and small block 350. Nothing particulary special about he car except it was purchased from a friend who was the original owner and we love it!

What we are looking for is a few suggestions on Motor, Trans, and Torque converter that work well with the car so we don't have to start from scratch. From the limited research we have done, it seems like the GM ZZ04 and 700R4 trans is a solid option. Will this "drop-in" without driveshaft or other significant mods?

What worked for your C3? Any suggetions would be appreciated!

Thanks/Regards,
JC

 

[blacksharkL82]

No motor vette?

Depends on where you want to go. ZZ4/ auto, is a nice street package, until some kid with a ricer pulls up next to you.
A mild BB, will do wonders, with an auto trans.
If I was doing it again, my wife would kill me for doing it, I'd go 450 hp or less, BB, auto, 3:70 gears. Could always dump NOX into it and have a ball, when you want it.
I'm wearing a flame retardant suit, so, I'm ready for the wars.

 

[yellow77]

Hey blackshark, I have a ZZ3, 10 less hp than a ZZ4, and even without the NOS, I dont have trouble with the local kids, and with the NOS, they dont want to play. ZZx engines and auto's make very driveable combinations with good power when asked for it.

Cheers

Richard

 

[goertz]

Folks,

The wife and I would like to purchase a crate motor for our 1970 vert project. We bought the car w/o engine so no rebuild possible. Car was originaly supplied with auto trans and small block 350. Nothing particulary special about he car except it was purchased from a friend who was the original owner and we love it!

What we are looking for is a few suggestions on Motor, Trans, and Torque converter that work well with the car so we don't have to start from scratch. From the limited research we have done, it seems like the GM ZZ04 and 700R4 trans is a solid option. Will this "drop-in" without driveshaft or other significant mods?

What worked for your C3? Any suggetions would be appreciated!

Thanks/Regards,
JC

If you don't mind changing a few things around, I'd go with the big block. Personally, I'd get a 454 crate motor, or find an early 70's vintage one, and paint it orange, make it look like it came in there, and put it in. 700r4 would definately be a good way to go. If you have the exhaust still intact, you'd have to modify a little there to hook up to the BB manifolds or headers, and engine mounts might be different. But there's nothing like a BB under the hood in my opinion. Personally, I notice very little handling difference between my big block car, and the small blocks I've owned in the past.

 

[blacksharkL82]

Vette build up

That's 2 of us that say go BIG BLOCK.
So much more TQ. You don't even have to try.

 

[Jack]

Dunno what your budget is ... suggest you establish some sort of range ... if nothing else, a budget'll help whittle down the suggestion box.Understand car has empty engine bay ... dunno if there's an existing trans? ... or its type & condition?I think you might also consider swapping in a gm LSx motor (chevy's current small block) ... lots of performance right out of the box ... tons more potential ... aluminum block-heads ... LSx available new from gm with fuel injection-ignition engine management controller ... or junkyard.

 

[Koop]

Folks,

The wife and I would like to purchase a crate motor for our 1970 vert project. We bought the car w/o engine so no rebuild possible. Car was originaly supplied with auto trans and small block 350. Nothing particulary special about he car except it was purchased from a friend who was the original owner and we love it!

What we are looking for is a few suggestions on Motor, Trans, and Torque converter that work well with the car so we don't have to start from scratch. From the limited research we have done, it seems like the GM ZZ04 and 700R4 trans is a solid option. Will this "drop-in" without driveshaft or other significant mods?

What worked for your C3? Any suggetions would be appreciated!

Thanks/Regards,
JC

GM ZZ383, 400 trans, 308 rear. I wanted to go to 700R4 and 373 rear but the mechanic said try it with the stock gears and trans...Crap this thing is fast! It's hard to get the car to hook up off the line! If I put any more power in the car I'd need to put bigger brakes on it.

ZZ383 425HP 460 Ft Lbs Torque

 

[ft laud mike]

My vote- bigblock crate (either 454 H.O, or zz454 ) the latter having aluminum heads price = h.o.-$4899.00 zz-$5675.00 . How do I know? Ive been searching for something new for my car as it gets painted
mike

 

[BarryK]

BB's are nice, no doubt about it and always tempting.......

I like the idea of the ZZ383 motor. Lots of HP, but even better it has a lot of torque like a BB but with the lighter weight of a SB. The lighter weight will also help the car handle a bit better.
One thing I've noticed though is that most of the ZZ383's come with a single plane intake manifold and for street use I think a dual plane intake would be better so calculate in the cost of a replacement intake also.
Sorry, can't help too much with the tranny selection for you.

 

[Koop]

BB's are nice, no doubt about it and always tempting.......

I like the idea of the ZZ383 motor. Lots of HP, but even better it has a lot of torque like a BB but with the lighter weight of a SB. The lighter weight will also help the car handle a bit better.
One thing I've noticed though is that most of the ZZ383's come with a single plane intake manifold and for street use I think a dual plane intake would be better so calculate in the cost of a replacement intake also.
Sorry, can't help too much with the tranny selection for you.

My ZZ383 didn't come from GM with a manifold, I had to buy one. The valve covers were butt ugly so those needed to be replaced, electronic ignition and deep groove pullys are helpfull since redline is now 6,000 rpm.

 

[BarryK]

Koop, I'm sure the motor can come a few different ways. The ones I saw all had single plane manifolds on them but for a small amount more could be purchased instead with a dual plane. I suppose they could also be purchased without any intake and carb at all as yours was.
Yep, I'll agree, most of the ones I saw being sold did not have the most attractive valve covers on them

 

[JimC]

Thanks to everyone for the comments. Yes, there is a tranmission in the car. I'm going to climb under in the morning to see if it's a 350 or 400. I just hope we can locate the identification tags.

All of the ideas sound great, but I'm concerned about having to modify the car for some of the BB options- as much fun as they sound. It's important to us to leave the car as stock as reasonably possible so we are looking for a "drop-in" solution.

At this point we are still strongly considering the ZZ4 to drop into the current mounts and bolt up to the existing transmission. We have been told that the bracket locations for the alternator, power steering pump, etc. or in different locations than the old Vette motors so one has to be creative in setting the motor up. I guess we are going to have to attend a Vette club meet locally to snap some photos of installed crate engines to see how this all works.

I've also heard that the ZZ4 has a one-piece rear main as opposed to a two-piece on the original motor and that can cause some installation issues. Since I assume people are talking about the rear main seal, I have now idea why this would cause any issues at all...

Oh yeah, budget for the trans rebuild, new torque converter, motor, alternator, brackets, etc. is 6k. The wife and I will install the motor ourselves.

 

[Jack]

GMPP HT383 ... MAY be better choice than ZZ4

Your Budget $6K overall ... Your 3-speed auto trans ... You install motor:
If you're NOT going to drag strip w/ serious intent ... I suggest GMPP's HT383 (not zz383) ... HT383 makes tons of TQ & HP ... TQ is what you'll feel & use most of the time (idle to 3500). You'd probably be much happier with cam & HP/TQ band the HT 383 has. DO NOT be put off or fooled by the HT 383 spec's suggestion as a "truck" motor replacement. HT383 is few bucks cheaper than zz4. HT383 cam & HP/TQ band won't require a higher stall convertor ... you might wish you had one w/ zz4. Both HT383 & zz4 have newer 1pc rear main seal ... as does ZZ383.

Primary diff 1pc v. 2pc is in the rear main seal (& its flange on block), crank & oil pan. Cranks have different bolt pattern on rear flange ... older 2pc flywheel will NOT bolt up to newer 1pc crank (& vv) ... older 2pc oil pan will NOT fit newer 1pc block (& vv). There are adapter kits to swap cranks-blocks but they are rather pricey. Final year gm installed 2pc sbc motors in production cars about MY1985.

HT383 has sturdier FORGED crank, zz4 NOT ... HT383 runs good on cheaper REGULAR gas, zz4 NOT. Purchase price of HT383 less $ than zz4. Although zz4's max HP is about +15, HT383 has more "balls" throughout your normal operating range than zz4 ... the "HT" means High Torque.

If you need an aluminum intake manifold to fit HT383's iron vortec heads & fit under your vette hood & fit either Qjet (spreadbore) or Holley (squarebore) carbs ... Professional Product's "Cyclone Vortec P/N 52007" can be had for about $110 ... essentially same as Edelbrock Performer vortec P/N 2116 @ about $160.
JACK:gap

 

[Tom Bryant]

Shortly after the HT 383 came out Hot Rod Magazine put Vortec heads and a different cam in one and pulled over 425 horse and almost exactly 500 ft. lbs of torque out of that thing with a mild idle and good drivability.

I'd lean toward the Ram Jet 350 though for the benefits of EFI in a stand alone package. I'd add a special built 700R4 from someone like Phoenix that is custom built for your combo and dyno tested before shipping. Around $1400. with converter and eveything to do the swap. You would have great mpg and road manners with a deep 1st gear for off the line stomp and that Ram Jet looks cool. Not sure if a BB hood would be required for clearance though.

A THM 350 has a square pan with one corner cut off. The 400 had an oblong pan with a more free formed curvy design. No mistaking the 2 as they are not even close in appearance. If your car still has the original trans it will be a THM400. The 350 was not offered in the 1970 Corvette.

Tom

 

[Bill75]

HT 383 Cost?

Hi Jack,

Real interesting facts on the HT motor. Just looked on SD site and ZZ4 is $3,789 while HT383 is $3999. No dist. in the HT motor, ZZ4 has HEI dist.

The fact that the HT motor runs on 87 octane and develops 340 hp is real impressive also.
I'm trying to figure out what the best solution is for me also to replace my L48 this winter so this is all great information.

Thanx Bill

 

[Koop]

Hi Jack,

Real interesting facts on the HT motor. Just looked on SD site and ZZ4 is $3,789 while HT383 is $3999. No dist. in the HT motor, ZZ4 has HEI dist.

The fact that the HT motor runs on 87 octane and develops 340 hp is real impressive also.
I'm trying to figure out what the best solution is for me also to replace my L48 this winter so this is all great information.

Thanx Bill

The HT383 doesn't have an intake or HEI or Fast burn Aluminum heads or roller rockers...Look at the cam, much to tame for a Vette.

The ZZ4 does have a forged crank and you get all the goodies the ZZ series offers. (A healthy roller cam and rockers, Fast burn Aluminum heads, high RPM etc.) You will not be bothered by the cam in this motor and all of your vacuum systems will work fine.

If for some reason you do have a TH350 trans, I ran one behind a mild LT1 in a very heavy '53 Chevy pick up for years, the guy I sold it to still has it in there and it works fine.

 

[Jack]

Hi Jack, Real interesting facts on the HT motor. Just looked on SD site and ZZ4 is $3,789 while HT383 is $3999. No dist. in the HT motor, ZZ4 has HEI dist. The fact that the HT motor runs on 87 octane and develops 340 hp is real impressive also. I'm trying to figure out what the best solution is for me also to replace my L48 this winter so this is all great information. Thanx Bill

Apparently the prices have flip-flopped ... seems the zz4 internals have changed too. I've been into several zz4 motors ... those did not have aluminum fast burn heads ... but they did have vette L98 58cc alum heads w/D-port exhaust ... they did have cast iron cranks ... apparently some or newer zz4 ship w/ forged cranks ... reporting what I put hands on. The ZZ383 does have FB Al heads and a forged crank ... it's based on a HT383 short block fitted w/ FB Al heads & bigger cam.

HT383 crate ships w/ iron Vortec heads and aluminum Vortec intake manifold. Distributors available aftermarket: new tach drive HEI $175, new NON-tach drive HEI $100. BTW, fast burn describes a very efficient shape of the combustion chamber (kinda heart-shaped) ... Fe vortec employs same design as FB Al ... L98 Al is similar but is not the same.

Take a look at HRM's HT383 buildup article Tom mentioned ... don't just look at cam specs ... look at dyno curves ... look WHERE hp/tq is made ... not just max ... compare those ranges amongst motors you consider ... are the ranges suitable for your use? ... street or track? BTW, it isn't mentioned in the article, but I checked and was told by author that dyno tests run w/ high octane (not 87). But look at the baseline initial tests/curves ... before they added a bunch of parts ... you'll see a stock HT383 packs a heck of a punch ... looks plenty adequate for a street vette ... easily capable of rpm ranges most folks use most of the time on street.

No dispute there're CAC folks who like zz4 in +3300 lb street car ... but I'm certain of the local guys who don't. A few of our regional asphalt circle track supertrucks run crate zz4 ... they run good and hold up real well ... but their rpm is quite different than typical street ... supertrucks w/zz4 avg rpm constant 5600-6300.

I also like the ramjet 350 for street ... really like that stand-alone EFI feature ... great combo if budget permits.
JACK:gap

 

[Koop]

The cam specs are important in my book, I like the way a good cam sounds it's all part of the experience of driving a Vette like that Vette smell when you open the car door after it sat for a week or the rear view mirror being water damaged from years of leaky T tops. NO CAM NOISE? WHY THAT WOULD BE LIKE AN OLD PORSCHE WITHOUT RUST! I like the wow factor when I open the hood and see all that Aluminum and I like to scream out 5,900 Rpm when I'm tearing up some expensive German Iron with my Bright Yellow 37 year old Chevy!

 

[Evolution1980]

JimC,

I apologize right now, for I didn't thoroughly read every reply up to this point (HT383 -vs- ZZ383 -vs- ZZ4), so this may be old or irrelavent news now. However, looking off to the left of this post to see what I've got...

I have run a 13.4 second quarter mile (and will be lower after I've dialed in the carb and timing) and have a top speed of 150+ mph. I can tell you that it's plenty fast enough to take most street cars, imported rice or not.

The ZZ4 short block gives you enough get from the go and also gives you room to grow ("build"). I'm looking at taking mine to a 383 or ZZ430 spec. However, on the ZZ430, only the HP really increases. That in itself is not enough to make me jump yet. (HP is for bragging, Tq is for winning races.) Hence why I'm looking to a 383 upgrade.

Since I'm used to the ZZ4's power now, I'm looking/wishing of the 502ci. However, that's out of both mine and your's price bracket. Heck, I'd even settle for a 396 at this point, hahahah :L If you have the TH400, I believe it should be able to handle a ZZ4 without any mods (355HP, 405 Tq). Otherwise, I'm loving my 700R4. It was built to handle up to 500HP and Tq. So I've got room to grow there as well. There's nothing like having the off the line grunt, and then being able to cruise 70mph at 1900 rpm!

If you look though the Scoggins-Dickey catalog (which either you or someone else mentioned above), you can see all the different spec on the engines. With a $6000 spending cap, you doing most of the labor, AND having a TH400 as a base, you should be able to get a pretty aggressive crate engine without too many other obstacles. I'd think you may have to check out a differernt exhaust setup, however the '70 wasn't emissioned in any way (I don't think), so that might not actually be an issue afterall.

My only beef with going to a newer engine (LS?) is that then you need to start dicking around with computers and wiring harnesses, sensors, blah blah blah. To me, it's so much nicer to only have to deal with carburation and vacuum. If it's not one, it's the other. Pretty simple. Plus, I think big ol' carb setups just look more traditional and impressive. Plus, I love the sound you get from a carb'd engine versus that of an FI'ed engine.

If it was my buck, I'd be choosing the 454HO over the HT383.

• 425HP -vs- 325HP
• 500Tq -vs- 415Tq
• 8.75 compression -vs- 9.1 compression

$900 is the price difference, and it's still way under your $6000 price cap. 100HP more, 85 more Tq for $900 seems like a no brainer. (And don't kid yourself, you're going to run premium gas in either setup, so that's a moot point for consideration, IMHO.)

Jack,
As far as I'm aware, the ZZ4 never had the GM Fast Burn heads. Those were specific to the ZZ430, which when it was introduced (with the intro of the FB Heads), was a limited production run of 430 engines. Now it's a regularly produced engine. But that's still now one (but not all) of the differences between the ZZ4 and ZZ430..the Fast Burn heads.

 

[Bill75]

Jack/Koop, Thanks for the feedback and good information!

Evolution, great feedback. I think the bottom line here is it seems like we're never happy with the power once you get used to to how it performs and we want to upgrade it. That's part of the fun in this hobby I guess, sooner or later we'll be looking for the plans for tie down straps for that F-16 engine . I find myself creeping up to the next plateau in HP when trying to decide what's best for my needs every time I learn something else and have to give myself a reality check pretty often.

Sorry Jim C, not trying to hijack your thread.