on a 89 chevy 350 what size cc are the heads?

I own a shop, and build a lot of race engines. Don't assume anything about the heads you have. A couple of good places to get the skinny on them is, www.kbsilvolite.com and you can figure your compression with their calculator for free. Also; if you will go to www.chevyhiperformance.com and do some looking around you will find where they did flow tests on about every head known. This way you can make an educated decision rather than just guess. Just because a head has a low cc does NOT mean it flows good. Some of the Vortec heads are crap, while the others will make the engine get up and talk to you. Do your calculations; and if you got to, have the heads milled to bring them to what you want. Chevy high Performance is a very good magazine, and they do a lot of testing on many combinations. Keith Black pistions (kbsilvolite) has a calculator that can put you in the drivers seat when it comes to building your engine to make the desired compression ratio you want. Too small of a cc head will make compression, not flow good because of the quench area being restricted, and will cause detonation that will destroy your pistons. This rings especially true with cast iron heads. You can go a little lower on the cc with aluminum heads, due in part because they disipate heat well, and don't have the (spark knock) detonation of a regular head. You can get a pair of Vortec heads complete from the dealer for under $500 that out flow most aftermarket heads. Now, what's not to like about that? Another thing; if you are building a stroker, don't forget to purchase a balanced rotating assembly, and do your grinding on the block so it will clear ok, or you will have a motor that will come apart.

Glad to help out, Good Luck!!!

i own a shop and those would be a fairly good set to work with ,they should be 64 cc, if not they could be 305 heads also,a lot of the late 80,s and early 90 models 350 engines came with the 305 heads,they ran better ,its like setting off a stick of dynamite in a coffee can, it made them run better because it created a better combustion area for them ,good luck hope this helps.

89 350's were Vortec I believe. EFI or TBI. Should be 64cc heads. Have them reworked and they are awesome flowing heads....