O.K. heres the deal my father in law has a salvage yards so I can get any of these heads for free. The question is i have a 305 l03 right now with the swirlport heads and I am wanting to do a cam swap and i heard that these heads will hold back any cam upgrade from reaching its full potential and im wanting to get rid of them the imformation im about to post is off of www.mortec.com i have three sets to choose from ,
1st set 3973487....71-72...350..........used on 71-72 350 LT1, 75cc chamber
2nd set 14102193...87-up...305/350......1.94"/1.5" valves
3rd set 3774682....60-64...283/327......70cc chambers
I wanna be able to rebuild the heads upgrade the valves and port them and use them on a 355 that im going to build at the first of next year for it I'm just going for a better power range out of the l03 that i have right now until i get the money for the 355.
please give me your thoughts on these heads i know there are a plethra of aftermarket heads out there but dont have the money to put into a set right now. any and all replys welcome.
thomas

 

The 682's won't have accessory bolt holes. Don't know about you, but that'd be a big deal to me.

193's are swirlports, I believe. No good. 083's would be okay.

Looks like those old LT-1 heads are all that's left. Big chambers, so you'll need flat-tops in a 355 to get even low-end street compression, and domed to get performance compression. Not ideal. They'd absolutely kill a 305.

Look for a set of 083's and work them over. I wouldn't bother putting them on the 305, though. If you want to warm up the LO3, find some 081 heads (hey, you're getting them free, right?).