I have just purchased a 350 SB out of a 1988 GTA. The engine has been bored out 40 over. It has a brand new Eagle stock crank, light-weight connecting rods, and hypereutectic pistons. My questions is about heads and cam. I would like to know which heads, springs, valves, and cam to purchase to produce a good amount of power (350 hp). I am new to engine building and I would greatly appreciate everyone’s help!

 

I'd look into Air Flow Research heads if you have the money. Course there costly... SBC 195cc Street Heads — $1275/pair Shipped from Tenacious Performance.

Make sure you pay attention to the compression ratio with your new pistons. Would suck to end up with 8.5:1 on a natural aspirated motor.

 

Depends on your budget and how streetable you want the car to be. AFR 195s and a CC305 would be an excellent combo. I installed this setup on a friends L98 with Hooker longtubes, SLP runners, ported plenum and base and it made 317rwhp and the car runs 12.67 with an auto tranny and 2400 stall with 3.73's and is so consistent it's scary. Got a chip from Ed Wright and it was as close as you'll ever get to dead nuts on. The Brodix Race Rites are another option and I think a little better than the AFR's if you get them with the CNC'd chambers. Low lift flow kinda sucks but proper cam choice can negate some of that. The Brodix are a little more money, about $1400 assembled.

 

First off, I greatly appreciate everyones advice. Like I said before, I am very new to putting an engine together and I want to make sure that I do it correct the first time.

The car is mainly going to be driven on the street. I doubt I will be taking this car to the strip. I just want to have enough power to roast most of the **** burners and Mustangs on the road. I have 2 sets of heads. 1 set is the stock heads that came off of a 350 and I also have heads off of a 305 TPI. I'm not sure if either of these would be a good choice. I'm sure both sets would greatly reduce the power that could be generated from this engine.

The pistons have 4 "D" shapes in the top of them. I'm not sure if that helps with determining the compression ratio.......

 

Here are the part numbers for my engine components:

block is 2 bolt main, ARP main studs, milodon diamond stripper windage tray
Eagle 5.7" press pin lightweight rods (SIR5700BPLW)
Federal Mogul hypereutectic pistons (H345NP40)
Moly rings (E251K40)
Clevite rod & main bearings
Eagle stock replacement new 350 crank

 

You asked what heads/cam would make good power on that motor. You never said anything about already having a couple sets of stock heads. Wether or not you take it to the strip makes no difference. If you want to beat most of the riicers and mustangs on the street you'll need to make some power because there are more than a few out there that are at least in the mid to low 12's.

Build the L98 heads. Get them magged, true the decks, cut the guides and spring pockets, get a good set of springs, retainers, guidelplates and rockers and get a good valve job on them. Bolt them on and slide a hot cam in it. That's as big as I would go with those heads or similar. By the time you work the stock heads though you'll probably have 8 or 900$ in them and for that you can almost have a set of the Dart Platinum heads that will make more power.

There's 4 combos that will make power for you. Don't forget you'll need the rest of the bolt ons to take advantage of the heads/cam. You'll need a good set of headers, full exhaust, stall converter and intake mods.

 

The pistons have 5cc volume, so you probably don't want to use the 305 heads. I'm using the 10cc pistons of the same type (.030" over, though). With 64cc heads, .020" compressed head gasket, .026" deck height, that calculates out to about 9.7:1 compression, handles regular unleaded just fine.

You can do some pretty good things with the stock L98 heads. Whether you spend the bucks to get guideplates installed, which will require pulling the press-in studs, having the stud mounts machined & tapped, and getting the plates & screw-in studs; or pin the press-in studs and use self-aligning rockers, is your call. The latter is certainly less expensive.

You can do a basic porting job on the heads yourself, which will really help their performance potential. Larger valves of the 2.02/1.60" variety will also help, provided you have a cam that will take advantage of them. If you can afford one but not both larger valves, go for the 1.60" exhaust valves. When you're done with the porting, have the valves done, cc the chambers, and have them milled to no less than 64cc if the decks need a clean-up. Upgrade aftermarket springs should be considered a must-do, ditto the guide/seal work recommended by Dialed.

You haven't mentioned what induction you plan on running. If TPI, forget the large valves and big cam, it won't like it. Probably won't realize your power goal, either, without expensive aftermarket parts.

A decent street/power cam is the ZZ4. You can get one fairly cheap on eBay.

 

I am planning on running the stock TPI induction with the exception of going to larger fuel injectors (24#?). What other type of induction systems should I consider? I really like the look of the stock TPI system, but I am willing to change if it compromises my power output. I never realized that the TPI induction had so many limitations. Is there any way to manipulate the TPI Induction so that it will work. I also forgot to mention that the engine came with a Pete Jackson "Quiet" Gear Drive. I have basic engine knowledge but heads, valves, and cam are like another language to me.

 

Reports are gear drives mess with knock sensors. You might want to consider a standard timing chain setup. The gear drive is complete overkill in any case.

TPI runners are tuned to produce max power at about 4500 RPMs. Plus, they are flow restricted. At a minimum, you should get aftermarket runners, which will be shorter and fatter. They'll change the look of the runners, but the overall look will still be intact (I, too, think TPI is one of the best looking induction systems out there). The plenum and base should be ported, unless you go for an aftermarket base as well. Most use a larger TB, such as 52 or 58mm, but considering the Ram Jet 502 uses a 48mm TB, same as the stock L98, and makes 502 HP with it, kind of makes you wonder (of course, the other characteristics are completely different between Ram Jet & TPI).

You probably don't need 24# injectors, although they probably won't hurt anything. Adjustable fuel pressure regulator is a tuning must have.

 

What are your thougts on the SLP Intake Runners (Description Below). Also, are there instructions out there for porting the intake manifold?


SLP Intake Runners, 1989-92 Camaro/Firebird/Corvette SBC
SLP's high flow cast aluminum TPI intake runners are the result of countless hours of dyno testing, flow bench studies and in-vehicle development. They have optimum runner volume and divider lengths to maximize airflow, and produce up to 20 additional horsepower over the stock runners depending on the application. They are cast from OE-quality, aircraft grade aluminum and precision machined for a perfect fit. These runners are an easy bolt-on upgrade for the 5.0L or 5.7L engine in 1989-1992 Camaro/Firebird/Corvette. No additional modifications are necessary. All necessary hardware and gaskets for proper installation are included along with complete instructions. They are legal for street use in all 50 states. E.O. D-187-9