Well finally pulled the trusty 300 out of my truck today, thought about dropping in a V8, but no I will not do that. So I took off the head and am getting ready to drop it off at the machine shop. What head work would you recommend, I plan on a barrel intake and carb, with a good cam, headers and good ignition system. Please give me your thoughts, need a list for the machine shop to go by..Thanks. Do I drop bigger valves in it, and how big. what about screw in studs, I think I would like to go with Roller Rockers, what is involved with installing these. By the way the truck is a 1965 ford f-100, the engine is a 1975 I6. Thanks again....

 

I am in your situation and here's what I am doing:

I am sending a 240 head in next week to be cut for 1.94"/1.60" stainless swirl polished valves, bronze guides, screw-in studs. I am not milling the head because it already has small chambers ('67 vintage) but I AM having both the block and manifold sides surfaced.

I have polished the chambers and blended and opened the bowls slightly. The recommendation here is not to get crazy - just to open the bowls a bit and clean them up. Keep the intake rough (40 grit) but get the exh. nice and smooth.

When it comes back I will port-match with dual EFI ex. manifolds and an Offy C-series.

The only issue to be resolved is how I shim the springs - after the 3-angle valve job (do it, you'll get much better low-lift flow) I will be working with about .200" more valve stem. The question is how do you compensate for that? What combo of retainers/shims?

Also keep in mind that you will need longer pushrods. What I am going to do is order a checking pushrod and a set of checking springs to ACCURATELY set the geometry with the roller rockers.

Any thoughts by anybody else regarding spring installed height?

 

Ok are you getting the extra .200 of valve stem because the bigger valves have longer stems

 

Actually they have .110" longer stems, I am guessing on the other .090" - about that has to come off the seats when they are cut.