i have a 305 in my 86 iroc z and i have three of the manifold bolts break off in the heads(its been this way since i bought the car 6 months ago) anyways the bolts are already drilled and who ever did this messed up so they can't be backed out. so i have a set of heads off a 77 chevy pickup for a 350 small block. does anyone know if i can just swap the heads out and use them? if i can then what's gonna be different performance wise? thanks a lot.

 

Those heads would turn a 305 into a complete dog.

 

if you're already taking the heads off why not drill em out all the way and retap the holes? or Drill and helicoil the holes? Or takem to a machine shop and have them do it? Also a good time to port em

 

does this mean good like beast powerful or bad like run like ****?

 

bad, like run like crap.

 

Those heads turned a 300 HP 350 into a 165 HP one.

YOU do the math as to what they'll do to your 160 or whatever 305.

 

well then.... forget this idea... anyone know any 305 heads that are good but not extremely expensive?

 

i have some heads ill sell u for that car cheap that come off a 86 iroc and has been re done

 

i take that back there off i 1985 lb9 305

 

305 heads are cheap.
416 castings, 601 castings, or the 081 castings intex has would all work.

The first 2 I mentioned use perimeter bolts, the last one is center bolts.
I wouldn't bother with 187 TBI heads.

I think removing your broken off studs would be easiest though.

 

Yea... 305 heads. They are everywhere, and they are dirt cheap. 416, 601 and 081 are the casting numbers to look for. 416 is by far the most common.

 

you should just port them, unless you get ones with better flow

 

What's wrong with taking the ones you have to the machine shop and getting the bolts taken out? Maybe a valve job and all that at the same time?

 

well i was thinking about getting better heads altogether but in the end it all comes down to me actually taking the time to take the motor all apart. i would start now but my i just blew the heads in the truck so i wouldn't have anything to drive. thanks for yalls advice though we'll see what happens when the time comes.