Thread: Surprise under the hood

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Assuming you wish to proceed as a 327, I will resist the urge to try to sway you into a 350 or 383, which might be way more fun with a 4-spd.

I'd begin by inspecting the main bearing bores for being round and parallel with each other and correcting as necessary. Then I'd register the block on the main saddle and cut the block decks to 8.996". This will produce a zero piston deck height with the reciprocating assembly stack of parts that I'm going to suggest. The main reason for cutting the decks in this fashion is to prepare the block for aluminum heads. Most all aluminum head manufacturers will spec a ~0.040" compressed thickness composition gasket with pre-flattened fire rings to minimize brinelling of the aluminum head surface, so in order to set the squish at 0.035" to 0.045", we will begin with a zero deck and make it easy, using a Fel-Pro 1003 gasket that compresses to 0.041". With a zero deck, that gasket thickness will describe the squish, 0.041".

Trying to find good parts that will leave your wallet in decent shape, I would choose these pistons.....
http://www.summitracing.com/parts/sl...make/chevrolet

If I were going to change rods (highly recommended), I'd probably use these.....
2570020P - Chevrolet 5.700 I-Beam Connecting Rods

Piston compression height is 1.671", rod length is 5.7" and crank radius is 1.625". Total these up and find 8.996" stack.

Generally speaking, each cut of 0.005" to 0.006" (depending on chamber shape and size) that is taken off the cylinder head surface, chamber volume is reduced by 1cc. I'm suggesting that you cut the heads ~0.025" for a chamber volume of 60cc's. Rig up a burette, some rubbing alcohol and some food coloring and cc the chambers yourself before you go any farther.

Now, let's calculate the static compression ratio. Our target would be 10.0:1 to 10.5:1 SCR for use with aluminum heads.

.7854 x 4.04 x 4.04 x 3.25 x 16.387 = 682.7 cc's.
zero cc's in the piston deck height.
60 cc's in the chambers.
5.4 cc's in the piston crowns.
9.1 cc's in the gasket.

Add all values together and find 757.2 cc's
Subtract one cylinder volume from total volume (757.2 less 682.7) and find 74.5 cc's
Divide total volume by 74.5 and find 10.16:1 static compression ratio with a 0.041" squish.

Use Howards 111145-12 retrofit hydraulic roller cam and Howards 91164N retrofit hydraulic roller lifters....
http://www.summitracing.com/parts/hr...5-12/overview/
http://www.summitracing.com/parts/hrs-91164n/overview/
This cam, installed straight up on the marks, will produce an 8.78:1 dynamic compression ratio and the motor should make good power and operate detonation-free on pump gas.

Top the motor with an Edelbrock #7101 RPM intake
http://www.summitracing.com/parts/edl-7101/overview/

, 700/750 carb, 14" x 4" air filter assembly so the motor can breathe and 1 5/8" long-tube headers. Choose 3/8" minimum flange thickness to minimize curling up and spitting out the gaskets. Resist the urge to use those fosdick shorty headers. In my opinion, you might just as well walk out to the curb and toss your cash into the street. Construct an H pipe or X pipe immediately after the collectors, then use mufflers of your choice through pipes of your choice all the way to the rear bumper. Pipes that are terminated under the car sound Ricky Racer and will get on your nerves after a very short period of time due to reverberation of the exhaust note against the under-car sheet metal, making you not want to drive the car any more.

The intake can also be found used under Holley part number 300-36 and Weiand part number 8016. Other intake manifolds that will work and can be found new are Professional Products #52021 and Weiand #8150. All these manifolds are dual-plane, high-rise designs that were patterned after the factory intakes found on the '68 and '69 Z-28 Camaro 302's. Best idle to 6000 manifold. Period.

With a 4-speed car, you can use a double pumper if you want to, although your wallet might not like it. Vacuum secondaries will be more mileage-friendly.

OK, that's the best I can do. Let's hear alternatives.....

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