would 89 350 heads work on a 305.

 

Define "work".

Fit? Yes.

Run as well as the 305 heads? Not if the 350 heads came from a TBI engine, and not if the 305 heads are TPI, carb, or crossfire.

 

305 heads are from 91 tpi 350 heads are from 89 tpi.how would a comp xtreme cam code/12-242-2 work in the 305?

 

You'd be better off to keep the 305 heads. The 350 heads are the same as your 305 heads, but with bigger chambers, which would probably drop you down to 9:1 or less compression (9.5:1 is what you are at with the 305 heads now). The very slightly bigger intake valve on the 350 heads won't make a difference with what you have, and the intake and exhaust ports are the same, so they won't flow any better than the 305 heads.

As for the cam... its all wrong for a TPI application, and is definitely on the huge side for a 305. That cam is designed for carbureted applications. Check Comp Cams website, and you'll see they also have a line of 'XE' cams specifically designed for use with fuel injection motors like your TPI. I would reccomend the EFI version of the XE262 cam (basically one 'size' smaller than the one you asked about). It would be a very nice cam in a 305.

 

thanks for the help.my car isnt a tpi any more it has a holly 600dpvs,holly blue pump,ajfpr,rpm performer intake,5-speed trans.would that cam work ok?

 

Its on the big side for sure, but it should be OK, as long as your compression is up around 9.5 or 10:1. I'd still recommend the XE262 for a 305 though.