ok i have a 86 iroc with a factory 305 tpi, just wondering here but first what does it take to upgrade to a bigger cam first in the engine then will it effect the computer at all,timing, things like that, then what a good mild cam, i was wondering if i should just put in the same cam that was in the 1985 305's that was sappose to put out 215 hp, also any other suggestions to get a few more horses would be appreciated..

 

Well if your rebuilding the 305 as im sure you can probably guess im going to mention its not much more work or money to go to a 350. If you didnt want to go that rout and wanted to keep the 305 I would still recommend looking into getting a post 86 305 roller block. The reason is with modern oils these old motors flat tappet cams do not typically fair too well and if your rebuilding the motor this would be a fantastic opportunity to swap to a motor that has provisions for a roller cam which solves this problem. Not to mention in addition to being more reliable the roller valve train would allow you to use a better cam. Just throwing a few thoughts out there. Now to swap the cam if you kept it mild you could get away without having to reprogram the ECM or do any machine work to the heads. You would still need new springs and all that good stuff you would do with any cam swap but beyond that it would be a strait forward replacement. You could use the 85 tpi cam that would probably be your best bang for you buck as you could probably pick one up cheap from your local auto parts store but better choices are out there. Just depends how much you want to spend.