TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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Hey guys, I heard that the corvette aluminum L98 heads have the same size combustion chamber as the stock 305 heads like in my 1991 Trans Am and that they give a very significant power boost and work well with the 305. Is this true? And do they bolt right in? If so I wonder if I can find a 'vette parts car close by...
Yes the combustion chamber is basically the same size, but the heads are aluminum so you will have a little more heat loss than the iron heads and this will sacrifice a few HP.
Ported, they may outflow the iron heads but I dont know that its worth the effort. Maybe on a 305 if you're stuck with it or have no intentions of getting a 350, ok. I would concentrate on the exhaust and maybe porting the intake first, then go after the heads. I dont know what you've done so far.
No they will not bolt right in. You have a 91, so the intake bolt pattern is different. You need an aftermarket base or you need to elongate the center 4 bolts. If you use the stock intake, your EGR will no longer be functional. There is also an accessory bolt hole you will have to drill and tap, if you want to put all the bolts back in that the car came with.
Yes the combustion chamber is basically the same size, but the heads are aluminum so you will have a little more heat loss than the iron heads and this will sacrifice a few HP.
Ported, they may outflow the iron heads but I dont know that its worth the effort. Maybe on a 305 if you're stuck with it or have no intentions of getting a 350, ok. I would concentrate on the exhaust and maybe porting the intake first, then go after the heads. I dont know what you've done so far.
No they will not bolt right in. You have a 91, so the intake bolt pattern is different. You need an aftermarket base or you need to elongate the center 4 bolts. If you use the stock intake, your EGR will no longer be functional. There is also an accessory bolt hole you will have to drill and tap, if you want to put all the bolts back in that the car came with.
Oh ok, well if they're not bolt-on then forget about it. Thanks for replying though!
