Question: ZZ5 engine swap 1981 Corvette

[bskdz]

Today I went to the local GM dealer to get pricing on a ZZ5 crate engine for my 1981 Corvette. The parts guy mention that there will be some bumps in this engine swap, specifically:

-)ZZ5 oil pan not fitting and will need to be modified for clearance..
-)going need aftermarket brackets for power steering, AC, alternator accessories, he was saying the ZZ5 mounting is different. Is this true?

Been doing a lot of research, and here's my questions that I'm looking for some confirmation answers:

-)81 flex plate is 14.13" O.D. w/168 teeth, ZZ5 comes with 153 tooth. Can I use my 81 flex plate and starter with the ZZ5?
-)what type of headers fit a ZZ5 engine in a 1981 Corvette? Suggestions?
-)Will the TH350c handle this engine? I will need a control lockup controller, comments on name brand?
-)going with Fast EZ EFI, in line fuel pump with a return line, Will hood clearance be an issue?
-)water pump is different, short on 81 vers long on ZZ5; can I move my 81 water pump to ZZ5?

That all I can think of for now.

I'm looking for some experience for someone that has done a ZZ5 swap into an 1981 or perhaps even ZZ4, I suspect there will be similar bumps in road with the ZZ4..

Thanks
Bernie

 

[frank_nesta]

The ZZ4 swap was easy. Change the water pump to a stock Corvette water pump ( use your original) and grind the head off of one of the timing chain cover. I do not remember which one but it is obvious. All of the components will bolt right up using the original brackets.

I just had a friend do a ZZ5 swap and he did not mention and major problems. I did notice that the intake manifold is different. The bolt pattern was different and there was no provisions for a ERG valve. So a manifold change is required. I will try to call him tomorrow to see if there are any other changes required.

 

[frank_nesta]

The ZZ4 swap was easy. Change the water pump to a stock Corvette water pump ( use your original) and grind the head off of one of the timing chain cover. I do not remember which one but it is obvious. All of the components will bolt right up using the original brackets.

I just had a friend do a ZZ5 swap and he did not mention and major problems. I did notice that the intake manifold is different. The bolt pattern was different and there was no provisions for a ERG valve. So a manifold change is required. I will try to call him tomorrow to see if there are any other changes required.

They told me that there is a dual intake manifold bolt pattern under the intake that comes with the ZZ5.
So it might be possible to use your existing intake?

 

[bskdz]

Thanks for checking with your friend on the ZZ5 swap. I'm keeping the ZZ5 intake, where I'm at we don't have emission testing. Would your friend be up to posting some pictures of the swap, I'm wondering what headers he used, and how much space he has around the headers. Also, the more I research, the more I'm thinking I'm going to have hood clearance issues... either new hood or a hood scoop.

The old motor and transmission are out. Found so far, radiator needs to be re-cored, and leaks at the upper rad hose, power steering hoses leaking, converting AC to 134a, getting quotes for a transmission rebuild and torque convertor replacement. Bought the FAST EZ-EFI on boxing day special. During the removal, this definitely makes sense to swap out the engine, there's a lot of "tired" components under the hood.

I'm cleaning the engine bay, and transmission cross member, I can clean to bare metal, and there is no signs of paint on the frame or cross member, this surprises me. Also the welding is looking like it was done a rookie welder, there's welding wire and the welds are very sloppy. I am surprise by the sloppiness of the welds and that the frame cleans down to bare metal, by just using degreasers.. Are both normal? Did these cars come with painted frames?

Really enjoying the project...

 

[frank_nesta]

Thanks for checking with your friend on the ZZ5 swap. I'm keeping the ZZ5 intake, where I'm at we don't have emission testing. Would your friend be up to posting some pictures of the swap, I'm wondering what headers he used, and how much space he has around the headers. Also, the more I research, the more I'm thinking I'm going to have hood clearance issues... either new hood or a hood scoop.

The old motor and transmission are out. Found so far, radiator needs to be re-cored, and leaks at the upper rad hose, power steering hoses leaking, converting AC to 134a, getting quotes for a transmission rebuild and torque convertor replacement. Bought the FAST EZ-EFI on boxing day special. During the removal, this definitely makes sense to swap out the engine, there's a lot of "tired" components under the hood.

I'm cleaning the engine bay, and transmission cross member, I can clean to bare metal, and there is no signs of paint on the frame or cross member, this surprises me. Also the welding is looking like it was done a rookie welder, there's welding wire and the welds are very sloppy. I am surprise by the sloppiness of the welds and that the frame cleans down to bare metal, by just using degreasers.. Are both normal? Did these cars come with painted frames?

Really enjoying the project...

The car is long gone from the shop, so no pictures available. The headers are Patriot Tight Tuck making sure you get the ones that fit D-Port cylinder heads. Since the heads will take your original intake manifold you have that option and can use your original hood if you choose to.

The frames were painted.

 

[72ZR-1]

I did a ZZ383 swap into my 72 last summer. No issues with the install other than I needed a new clutch, flywheel and starter. I used my Hedman headers and they fit the D port heads fine, but the above poster is correct other than these Hedman you will need specific headers to fit the D ports.

 

[bskdz]

ZZ5 discontinued HT 383 or ZZ383 base

Mid June, I ordered the ZZ5 and after 3 weeks, the parts guy emailed me, the ZZ5 has been discontinued! ZZ5 is even listed in the 2015 Performance Catalog. What the heck? Parts guy is suggesting HT 383 (340 HP & 435 lb ft) with Vortec heads or the ZZ383 base (425 HP & 449 lb ft) with fast burn heads...right now I'm thinking HT383 cause of the torque numbers, 87 octane gas, and there is one in stock. Thoughts?

 

[frank_nesta]

Mid June, I ordered the ZZ5 and after 3 weeks, the parts guy emailed me, the ZZ5 has been discontinued! ZZ5 is even listed in the 2015 Performance Catalog. What the heck? Parts guy is suggesting HT 383 (340 HP & 435 lb ft) with Vortec heads or the ZZ383 base (425 HP & 449 lb ft) with fast burn heads...right now I'm thinking HT383 cause of the torque numbers, 87 octane gas, and there is one in stock. Thoughts?

If you are just replacing you stock engine this will make you smile when ever you drive it.

 

[bskdz]

A quick update, summer has been busy with life in general, jumping back into the project. Bought the HT383, its arrived on my wife's B-day, a perfect gift, I also had a "plan B" gift. Moved the short water pump over, found the perfect bolt at Lowes, no grinding the timing chain cover bolt. Bought 168 tooth externally balanced flexplate. Measured intake on HT383 vers stock motor, HT383 intake is approx. 1 inch higher, could this be future hood clearance issue..? Bought a Sanden AC compressor with brackets from Nostalgic Air (great to deal with). Getting ready to put together the AC lines, also bought the AC line kit from Nostalgic Air. The headers are interfering with the AC bracket, will be adjusting the AC Bracket. Now working on fuel line plumbing for the EZ Fast fuel injection, bought the inline fuel pump, its a very complete kit just need to account for tapping into the existing fuel lines. Might be sacrificing spare tire to mount the inline fuel pump. Been seeing mixed messaging on using the existing 1/4 inch return line..some say yes, some say no and go bigger with 5/16 return line.. doing the research on this.

 

[72ZR-1]

Anyone who bought the zz5 or zz383 deluxe (450/450 @ 4500) is able to rec a $700 rebate. Advertised hp is overstated. To achieve the stated numbers you have to install a 160 thermostat, different roller rockers with peak occurring at 5200 rpm. Here's a number to call tel:888.462.6671; ext 1109 I'll post up an email addy when I find it .My ZZ383 is part of that group, couriered the original invoices and signed waiver last Thursday. Was told to expec the cheque in 6 - 8 weeks. The dealers are supposed to contact us, mine didn't I read about it on a forum.

"You need to contact the GM Dealer you bought your ZZ5/ZZ383 motor from….They will give you all the info ………you must be the original purchaser ,have your original invoice and sign a waiver, send it to GM…………you can call GM at " (888)980-6148….. Or Email ZZ5Engine@acbcoop.com

 

[bskdz]

Thought I'd send an update, yesterday me and a couple of buddies fired up the HT383...after working on this project for 17 months, on and off, in between everyday life. Did the initial program for EZ Fast EFI fuel system, and on the first try, engine only cranked...helps to connect the tack and batt connections to the distributor. 2nd try it started... had to help the EFI a bit with the throttle to keep the engine running, kept it around 2000 rpm and then let off the gas, the EFI hunted for idle 2 or 3 times and then it settle down. Pretty cool, now to figure out hood clearance and get it on the road.