how well would it work to use a set of 327 heads on a 305 with twin turbos? would that be too high of a cr for a couple small turbos?

 

a few things; what motor? some 305s came with flat tops, others with dished pistons. The stock CRs went from 8:1 to 9.5:1 from the factory. Secondly, what CC are the 327 heads? Do you have a casting # for them? Thirdly, if you have an 87 motor the intake will need mods if it's a stock one. Assuming you went from 58 to 64cc heads and no other mods (thicker HGs, milling etc.) you'd see about .65 of a point drop.

 

nothing too specific, just looking to see if it would be any better than a set of 350 heads

 

Need casting#s and valve size.

Also the older heads (camel hump) dont have accesory bolt holes in them. I ran into this problem back in HS with my Chevelle but it was easily fixed with brackets from a older non A/C truck. I'm not sure how to remedy that problem on a third gen.

kyle

 

i don't know casting #'s or anything, i have an lo3, i don't have any heads from a 327 or 5.3 literi was jusst wondering

 

Johnny, if you're interested I have some '69-'72 327 heads. Casting is 3932441 I think. They do have accessory holes. I think the combustion chamber on these is 75cc, and the valves are 1.94 and 1.5. If I'm right about these heads, they'll rip the bottom out of your compression ratio. I wouldn't run these on a naturally aspirated 305, (although someone did - these heads are on a 305 right now) but for twin turbos, maybe it's not such a bad idea.

 

i'd love to spend the money and buy the heads and run tt's on my 305, but i gotta paint my car and get it inspected first, and either way i don't have a ton of cash sitting around right now, just trying to get a feel of how well this setup would work.

 

Well if you decide at some point that these are something you want, I'll give you a very agreeable price. I'm probably never going to use them and they're just in my way.

 

Another thing is that you could use a set of TBI/TPI 350 heads. When it comes to 327 heads, there are few to none that are unique to a 327. The 327s used similar heads as the 350s, 302s and similar engines. Keep in mind that to use any old gen heads (pre-87) you'll need to slot the bolt holes. What's important to you is the casting numbers, and from that you can get specs on chamber sizes and other info (eg good/crappy performance) Mortec is super handy for this, you can see what you're getting into spec wise. Turbofast also is handy, you can see what a head chamber size change will do for you. You need to use the same bore and stroke, and past that I just fudge the numbers.

 

327 heads will be either 64 or 72cc, whether it works with your 305 depends on which pistons your 305 has and which heads you have, since you could realistically end up with a compression anywhere from the mid 7’s to the mid 8’s…

Either way I’d skip them if they have 2.02/1.60 valves, too big a hassle with a 305