performance mod ?'s

[c3sam]

it's been a while since i have made any mod's to my 77. i currently have a stock 350 bored out .040 with a stock cam and heads. minor modifications such as an aluminum intake manifold and flexlite fan. i also have holley super-competition sidemount headers blowin my exhaust. my tranny is t350 3 speed with a 2800 converter and an incredible shift kit. ive got about 260 hp on the ground as it is.

i am saving to buy myself a great birthday present. i just don't know what want and i'd like help from y'all.

this is the only option i've considered:

-swapping the cam for a higher-performing yet somewhat mild cam 268/272 ($200-225 and bumped close to 350 hp i've been told)
-then adding a vortech carbureted supercharging kit (requires no additional hood clearance) with a holley 4150 carb ($2600 kit + $200 pulley assembly + $400 carb = $3200 and between 30-70% more power, so almost 500 hp @ the more reasonable estimate of around 40%)

------ this option leaves me with room for great modification such as a head swap later, but will cost me $3400

im willing to spend barely over 3 Grand but the results hafta be worth it and i prefer not to swap the engine entirely (i've had bad experiences with blocks and i've finally found a shortblock that i trust)

please share any creative or effective ideas you have in great detail

thanks
sam

 

[silver 80]

Have you thought about the overdrive trany? I hear that first gear is great.
tom

 

[c3sam]

Have you thought about the overdrive trany? I hear that first gear is great.
tom

i really don't mind my first gear. my acceleration isn't bad. i do wish i had an overdrive. i'd like it on the highway. but my primary concern is power right now, its not everyday i spend that kind of money on power, its a special event for me. and i'm assuming that if i considerably increase my power, then i will save gas going 70 on the interstate because it will require less effort from the engine.

 

[c3sam]

i just checked the Procharger website. they offer several supercharging options for carbureted smallblocks, all for around $3K or less. they also claim an average 62% power increase over stock.
Procharger claims that centrifugal blowers work cooler with carbuetors than with EFI. they say the way the fule mixes with the charged air creates a cooling effect on the fuel when it atomizes. thus performing like an intercooled supercharger.

anyone have any experience with carbureted superchargers?

 

[lone73]

Putting out 500hp thru a stock '77 rotating assembly (crank, rods and pistons) sounds risky to me. I'd probably go for a good set of aluminum AFR heads now and do the blower after the next rebuild at which point you can upgrade the internals.

lone73

 

[Tom B Hargrove]

Lone73 is right. A good set of heads (and those are real good ones) will make you some serious hp. And he's on the money about the bottom end. A good crank, pistons and rods are good insurance. I'm using a comp cams 262 and it is a good mild street cam (good idle, good vaccum). My next project is a 355 with vortec heads and a xe274 with a rpm performer intake and a 750 Demon. I think I might be on the edge with this cam and PB's, I'll let you know how it does if you are still looking.

Tom

 

[Scooter76]

I just finished mods on my L48. You may consider going this route. XE262 cam, upgraded Vortec heads (good for .550) , 1.6 roller rockers, headman headers, performer intake, 600 vac. sec. Holley, TCI 2k stall converter. This stuff really awakened the little L48 . I spent around 2k for all the mods listed which isnt bad. Vortec heads are one of the best deals going. The out flow every iron head on the market with an intake port of 180cc or less. 239 cfm @ .500 lift. They are said to even outflow the cast iron "bowtie" heads out of the box, & they don't cost an arm & a leg, even for the upgraded versions. I would not trust the L48 rotating assembly with a supercharger, as said above. You should be able to make a reliable 375 or so with your 77 shortblock.

 

[Scooter76]

This may also intrest you, if you haven't seen it already.
http://www.corvettefaq.com/c3/goodwrench/GM Goodwrench 350 test part 1.htm