I have an 88 305 TBI AT 2.73open dark red metallic SC. All stock. Not for long.

I am acquiring some parts for it to hopefully gain 25-35 HP.

I already have acquired but not installed
1) 1989 L98 cam
specs
10066049* .415 .430 207 213 117.0 (116/-118)
2) 36mm hollow fron swaybar, wonderbar, BZX/NNL springs
3) L69 ypipe

Within two weeks I'll have
1) 89 L98 cast iron heads
2) 89 L98 exhaust manifolds
3) KYB struts/shocks
4) Ti22 brake pads for front and
5) ES poly tranny mount and torque arm mount.
6) lakewood LCA's and adj. panhard
7) pacesetter 3" cat back ($134 from JCW)

Now, as i understand it ... everything is exchangeable within reason.

I believe I'll have to move my AIR tubes to the L98 manifolds due to the inlets pointing in different directions. Is that right?

I think the L98 exhaust manifolds will bolt up to the L69 y pipe and end up in a close to stock position that won't beat on anything. is that correct?

I need a new cat anyway due to mine rusting/blowing out from being a low mileage sit around a lot 1988 car. Can you recommend a cat that is inexpensive and will work well between the L69 y pipe and the pacesetter 3" cat back

I am not sure but i think the L98 iron heads are 60cc, I think my swirl port 305 heads are 58cc. I'll loose some compresiion but as best as i can reason it should way overshadowed by the much heavier breathing.

I know I am a novice at this so tell me if I am venturing down a dumb path.
If I am venturing down a dumb path that is in no way workable, I will just stand tall and get a 400 or 350 1 piece rear main seal rebuilt or used block and proceed on alternative plan

1) pull and disassemble my engine
2) get my crank and rods all cleaned up
3) get new piston and rings
4) put my crank,rods and new pistons in the 350 or 400 block.
5) put amelling high volume oil pump in it
6) do a home job of polishing the exhaust ports and gasket matching the intake ports on the l98 heads, and get them professionally rebuilt.
7) get a fedral mogul timing chain
8) put the l98 cam in the block, reuse good
stock roller lifters and replace any that need it.
9) get a 87 up performer intake with EGR
10) put the engine back in and start reassembling all the peripery.

I need low budget yet reliable high performance. the thing I am shooting for is a large flat torque curve and decent HP peaking around 4600 to 5000 rom. With the high torque coming on down low I will need a real good hook up off the line also.

I am still to confused to start takig things apart and having at it or will either path get me down the basic hot rodder road to a much more fun camaro to drive?

Any advice you can give that can give this 305 some long lasting torque from down low is helpful. Especially if you know of any stock combos that really work.

So far, the fastest STOCK 305's I have seen listing believable track times were running "551" heads. I don;t know anything about these heads do you?


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1988 Camaro Sport Coupe305TBI-4spdAOD-2.73open in "bought stock" condition. That'll change if it stays around here much longer mike.davis@firstunion.com

 

Are you sure your cast L98 heads are 60cc? L98 aluminum vette heads are 58-60cc, but I think the cast heads have a much larger chamber volume, but I'm not sure what it is. Consider this though, a vette 350 with 60cc heads has a compression ratio of 10.5:1, or something close to that. A L98 with cast heads has (uh, not sure about the exact number) something like 9.5:1. You might want to make sure you've got the info right on the heads because I have a feeling you're gonna lose a LOT of compression with those cast heads. Input anyone?
If you don't get any replies here, you might want to start a different thread titled 'CCs on cast L98 heads?'

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91 Z28
Come see The Vicious...

 

Iron L98's are 64cc. You'll lose compression unless you have them shaved.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4 (restalled TC). Ported World 305 heads, Crane PowerMax cam. ZZ4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster. 2.93 limited slip, Spohn SFCs. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
57 Bel Air, my 1st car. '66 396, 9.7:1 forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 700 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

I was thinking of putting L98 iron heads on my LB9 (305 TPI), they have 64cc combustion chambers, definately need them milled some to not lose too much compression. I'd say forget the L98 manifolds and get some headers(Edelbrock for TPI(3" y-pipe to cat)cheap $~320 w/everything for swap) The L98 manifolds are better than the TBI one's but for $300 the edelbrocks will give your whole engine much more potential and gain an easy 20hp over the L98 manifolds. I'd also recommend buying an new/used aftermarket cam. Something with more duration and more lift. Like in the 21x/218-224 int/exh and lift ~.500+" range. Sure the L98 '89 cam is better than stock TBI, but why not spend another $200-260 to get a cam that will give you 30-40+ more HP instead of 10-15hp. You're going to be doing the work anyways.

If you are going to go as far as rebuild heads and cam swap and take the engine out of the car. Do it right the first time save up for that extra $500-600 and get headers and an aftermarket cam. Those 2 things will give you more power gain (I say 40-50 more hp than the build up you stated) that all the rest of the rebuild. Headers are necessary(can't spell) to make good power. Get rid of that 2 1/4" cat/exhaust also, that is needed.

I don't see why you shouldn't be able to make close to 280-300hp with computer tunning and the TBI mods(bigger/injector spacer/all that stuff for fuel delivery).

My car has that 89 L98 cam you speak of stock and it doesn't impress me any.

Scratch that Exhuast stuff I see you plan on a 3" exhaust already (GET HEADERS).

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14.62@96mph headers, muffler, chip, ghetto stuff, duct tape
89 GTA 305 TPI 5 speed 3.42 gears