Bnine

What are the top 5 performance enhancements that I can perform to my '71 350 small block corvette get the biggest horsepower results? I am looking for about 340 to 400 hp total out of my stock 270 hp 350 small block. Here is a pic. [IMG][/IMG]

Weird Science

You don't give any qualifiers such as cost, ease of installation, etc.. But, here is my list-

1. Heads
2. Cam
Heads and Cam make power.

3. Headers (May be #1 for you cause this is relatively quick, easy, and cheap)4. Cubic Inches- Stroke it to a 383
5. intake/carb

IMO the work required to get sotck heads to 400hp would cost as much as a good/better set of aftermarket heads. No way to get to that level with stock cam either. Consider headers a must.

Bnine

I don't have any qualifying restrictions. My only restriction is that I do not want to permanently modify the original structural state of the vehicle. I do not want to bore over, but cam, heads, and interior engine components I'm OK with. I will be pulling the engine in the fall for rebuild, and that is when I want to get this done....
What would you suggest for intake/carb combination?, How about heads?, pistons?

Weird Science

It may be impossible to rebuild your engine without boring it over. If your concerned about originality, I would store your old engine as is and find a good core to build.

Need more info for recomendations. What is your budget? How much do you value idle quality?

75Rag

:iagree: Yank out your original and get something to play with .......

vette_c5c6

If you want your vette to rock, Let a pro-tune the sucker. The closer the specs are to the factory settings the more you will enjoy your vette. My 75 is as close to factory spec as possible, I turn the key and the beast comes to life and I get over 22 miles to the gallon on the freeway.

Boofers

Stickers Stickers Stickers! Stickers make your car go faster. Oh wait this isn't the Honda forum... Sorry! :jester

Dalannex

1. heads
2. cam
3. intake
4. exhaust
5. compression change during rebuild????????


-Justin

ddecart

That matches my list pretty well. Turning it into a 383 would be a possible item, too.

If you don't want to hurt the original engine and you're going to spend $$ on heads, cam, intake, carb, etc... then pull the original engine, stick it in a bag in the corner of the garage and leave it there. Small blocks are a dime a dozen. Buy a used engine, bore, stroke, and modify it until you're happy.

jrzvette

Don't know what you mean by permanently modify the original structural state of the vehicle. If you plan on rebuilding a 32 year old engine chances are it will need some "cleaning up" of the cylinders. A standard (.030) overbore will result in a 355 cu in engine. As far as anyone is concerned the only way to check that would be to pull the heads. So originality really isn't an issue.

Corey_68

HP for the $$$, NOTHING beats Nitrous. :D

adam

Reorder please...

1. exhaust
2. New motor, or
2. heads
3. cam
4. tuning...
5. compression
6. intake

Exhaust gives biggest bang for the buck. It also improves the result of
all the other things after it.

boredsoIstrokedit

:yesnod:

desi

:iagree:

Having been thru a few mods myself... Header is the first requirement. Biggest bang for the buck. Easy to do. Reversible in hours.

BSeery

Depends on the specs of the motor now. Do you know if it is a high compression motor now?

For the L-48's out there that are running that 8:1 compression I recommend the following.

1. Pair of L98 58 CC aluminum cylinder heads. Bumps up compression, get a nice set of aluminum heads, flows better than stock.
2. New intake - Air gap RPM or Performer RPM. Carb - 650 - 670 CFM should do.
3. Camshaft - 268XE or likewise.
4. Exhaust - headers, duals.
5. Ignition - get a good HEI with a good coil and module, or upgrade to a aftermarket ignition system.

$1500 ish and the stock L-48 motor does not even need to come out of the car.

bossvette

I agree if you are concerned about origionallity stick the stocker in a bag in the corner, then how fast do you want to go?(how much money do you want to spend?)how much work will you have to farm out? simplest way is a crate motor either GM or aftermarket. Headers are a must and fuel injection / OD trans is well worth the extra money.


[Modified by bossvette, 9:43 PM 7/23/2003]

MotorHead

Here's what you do:

1)Get it rebuilt 30 over use stock crank and rods and get some flat tops for 10:1 compression.

2) Buy a good set of heads

3) Get a good intake

4) Headers and dual pipes out to non restrictive (loud) muffers.

5) Get a cam somewhere arond 230 duration @ 050 and .470 - .500 lift

You will be good for 300 HP at the rear wheels which is impressive for a SBC :D

dath

Yep, I'll second that one. It's easy to install and remove, doesn't effect your normal running conditions any, and is there when you want it, doesn't cost an arm and a leg, has the "bling bling" factor... That's the route I'm going, well, of course that's on top of a 465HP 383 as well :D C'mon 11 second 1/4!

Redfish74

1. Bore to 355 dont worry about stroking it
2. heads bored
3. cam
4. headers/exhaust
5. intake/carb

I did all that and mine is a low 12 second car if you need more than that then stroke it.