I have taken out my 91 305, to put in my #3970014 .30 over. I believe this has a 400 crank in it because he told me the internals were forged and I've found that some older motors came with 400 forged cranks. I have the T-5 trans. My cousin, whom sold me the engine for $200, had the 700r4 in his. He doesn't have his flexplate anymore. Can I take my 153-tooth flywheel from my 91' 305 and have it "unbalanced" to match this older motor?

I have searched on the boards to find some info useful. But not an answer to this question.

Also will the heads from my 305 work on this new motor? Will i need to have the combustion chamber on the head milled to match the cylinder bore? I asked my local machine how much to check heads for deck straightness, cut valve seats, install new valves and springs, and he quoted me $175 does that seem fair?

 

That block is a '70-'76 350, 2-piece rear main seal type. They did not come with 400 cranks - forged or cast (and the factory didn't make forged 400 cranks). If it has a 400 crank in it, somebody put it in there to make a 383.

Most likely you have a plain, off-the-shelf, standard cast 350 2-piece rear main seal crank. Your '91 305 flywheel will not fit that crank. You need a 153-tooth 2-piece rear main seal flywheel for an '83-'85 V8 f-body application. The block may or may not be drilled for a 153-tooth starter, so establish that right now and save yourself major headaches later. The machine shop should be able to properly drill, tap, and ream the necessary hole.

Your heads will fit the block. Whether you should do that depends upon which 305 you have - TBI LO3, forget it. TPI LB9, no problem. No, you don't have to mill the heads to match the cylinder bore, but having them machined for 1.94" intake valves is a good idea. If he'll do that for $175 (along with what you already mentioned), that would be a decent deal. You also need to be conscious of the piston type, because 58cc chamber heads will need dished pistons on a 350 in order to keep compression down to reasonable levels.

 

The pistons are flat-top with valve relief. And my heads are the crappy TBI heads. So I Am thinking about just putting in the flywheel and then saving money for some new heads. Any suggestions on getting good torque/$?

The pistons are .30 over so I guess the builder did what you said five7.

 

Valve reliefs aren't enough to lower compression adequately. They are about 5cc, you need about 12cc total with 58cc chambers.

Consider this kit http://www.sdparts.com/product/SD806...keHeaders.aspx . Ignore the picture. The heads are 350 64cc chambers for about 9.5:1 with your flat tops. A bit pricey, perhaps, but an excellent baseline to build good power and torque.

What heads are on the 350 now?

 

Well, Right now there are NO heads on the thing! The previous owner was running TPI heads from the 305 with a tpi setup. He told me that the high compression helped him with horsepower. But i'd rather have performance matched components than just high compression.

I like your suggestion but I already have a dual plane intake manifold. SO i was looking at these heads. http://www.sdparts.com/product/DAR10...EagleHead.aspx

I thought that vortec heads could only go on 97 and up vehicles/engines?

 

Vortec heads only CAME on '97 up engines, but you can put them on anything. you just need to get a Vortec specific intake manifold.

 

'96, actually.

Performance-matched is the key. The Iron Eagles are good heads, but you need to have the rest of the package matched to get out of them what they can do - mismatching will be a recipe for disappointment.

What intake do you already have? It may not be a good match for the Iron Eagles.

 

Another good head choice http://store.summitracing.com/partde...5&autoview=sku

less $$$ too.

 

Right now my intake manifold is a Holley street dominator.http://www.holley.com/300-36.asp
It was on stock Iron heads and the 4 center bolt holes were filled in with a sort of epoxy by the previous owner. Clearing them out wouldn't be any problem. I'm going to a super chevy show @Moroso track this weekend and I'd like to buy heads there cause Parts are always mad cheap there. I'm looking for torque rather than HP. I was going to look for anything with high flow rate and combustion chamber size of around 64cc. Anyone have suggestions on what to look for @ the show when buying heads?