So here's the deal. I really don't care what the car will make for power I'm just curious. Im going lsx in a year or two so this build is mostly from sound and to show off. After driving built and loud cars for 10 years, this stock stuff sucks lol.

So, here's my proposed build
89 iroc 305 5 speed
Flowtech headers and y pipe
Catback (not sure yet)
Cat and air delete
Egr delete
camshaft around 202/218 111lsa or so
Port match and Siamese the runners using stock tpi parts
Air foil maybe
tune of course

I figure this should be good for 240 rwhp? Ive been building lsx motors for ten years but I don't have any experience with tpi. My first tpi car blew up after 2 months then was replaced with a lsx/t56 lol.


Like I said, this build is cheap, just for sound and some more torque to show off.

 

Less. I had a fairly worked 305 which had:

LT4 cam (not the hot cam)
AS&M runners
Edelbrock base
Ported plenum
Edelbrock headers
Flowmaster 3 inch exhaust
Air foil
throttle body coolant bypass
Descreened maf

All that with a good tune only netted 216rwhp on the dyno. It was something like 261tq too. Now granted it was a fun motor and car to drive but nothing like the 355 i built two winters ago.

 

That's it? Well I suppose you had a small cam. After reading that I may just do headers and cat back

 

i dont know the specs of that cam off the top of my head but yea it wasnt huge but it was noticeable at idle. You might put a bit more down to the wheels since yours is a t5 and mine was a 700. But 240 for just the mods your thinking is probably pushing it. Id guess a bit more than mine but not much.

 

I may just install a flat tappet kit because its so cheap to get the sound. Do you have any idea what a lb9 synod stock?

 

That seems about right for a lt4 cam as its not much different than stock LB9 or L98 cams. Typical bolt on 350 should be 230-240 whp depending. 305 would be down abit, 210-220 would be nice to see. Decent cam swap and tune could net 230-250whp i think but havent seen any done and documented. It wants to spin higher with a cam and if you allow it to with good ported intake and shorter runners it should respond

 

Yea to this day i will still dont understand why the former owner of this car decided on the LT4 cam and not something a bit more aggressive.

To the original poster, dont go backwards from a roller to a flat tappet. If your block is a roller stick with a roller. You will see more power from the cam upgrade. Honestly everyone hunts for the perfect sound but i care more about going fast than the sound. If it sounds good too...then bonus.

 

I'm just looking for sound. I really don't care about performance since I'm dong an ls swap

 

Anything of decent duration is gonna sound. Id order a comp xe grind around 218 duration at .050 on a 106-108 lsa. That will thump alittle lol

 

hmm got the same issue dump the 305 and get a crate motor or keep it