whitetrashT/A

Quick question:

What's the biggest valves you can fit on a 305? Would 1.94/1.60's work?

Thanks.

ws6transam

1.94's and 1.60 will work, but you will need to lay a cylinder template onto the combustion chamber, then carefully enlarge the cylinder head around each valve. Otherwise, your valves will be shrouded and airflow will be worse than the smaller valve. The 1.60 exhaust valve might not fit without some careful machine work and some fancy valve seat inserts, either...

You'll also need to do extensive bowl porting underneath the valves to match the new valve seat contour.

See: http://www.ws6transam.org/ported.html

whitetrashT/A

Thanks for that link. I've already been doing some porting on a set of 350 heads that I picked up for free. I was just going to use them for practice but they're turning out so well that I think I'm going to rebuild them and slap 'em on a motor.

The reason I was asking about the 305 is because we just got a core 305 here at work. It runs fine and if I pay the $100 core, it's all mine. I think it'll be a little more fun than the 2.8 thats in my firebird now.

sheppard00

the 1.94 and 1.6 fit in the head without needing new seats ect... the chamber will need to be unshrouded and the portwork helps quite a bit. good luck on your project.