i have the oportunity to buy a pair of rebuilt stock 350 heads, with the casting 193, my question is can i bolt these on to my bone stock 305, and if i can is there anything else that i need to do it?, and if i can bolt them on, how much extra horsepower will i gain?

 

1. yes you can bolt them onto a bone stock 305
2. there should be nothing extra needed if your 305 is TBI
3. IMO the hp gain will be zero, or less.

The 350 heads has slightly larger intake valves, so they will flow slightly better than the 305 heads BUT the chamber is larger so your CR will drop and that will slow the burn speed -- resulting in slightly worse fuel economy and slightly worse power. So I don't think there would be any power gain.

To get a useful power gain, you would need to mill the heads to decrease the chamber volume and maintain your stock CR, and if you went to that trouble then you ought to port the heads (beak removal on intake ramps, radius/smooth all valve stem bosses, general port cleanup). Porting and milling would give you a big power gain (duh) but doing what you suggested won't. IMO.

 

thank you very much, i dont think im going to get them, i will probably just end up getting the stock 305 heads ported and milled, here is the ebay link if your interested in them, http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=008