351C 4V heads
Thread Starter
|
Freshman User
Joined: Jan 2003
Posts: 34
Likes: 0
351C 4V heads
I have a used set of 351C 4V quench heads modified for screw-in studs and with valve guides installed. On one head, in the bowl area, on the exhaust I noticed the cast iron boss supporting the guide is thin and partially broken away on one of the heads. The heads have seen some hard use in a dirt race car but seem in good shape other than the chipped boss. I'm looking to have these heads re-done with all new hardware. I thought I might have the bosses cut back on all the exhaust valves to eliminate the chip and improve flow across the board. The bosses would have to be cut back .38 to .50 inch. With the bosses cut back the guide will protrude unless I cut the guides back also. Should I cut the guide back flush with the boss or leave it protrude beyond the boss? Should I cut back both intake and exhaust? Anyone ever done this type of thing? Any thoughts appreciated.
Posting Guru
Joined: Dec 2002
Posts: 2,003
Likes: 2
From: chicago burbs
351C 4V heads
here's a site i refer to often, good pics, info
http://users.abilene.com/~dkelly/hotrod/newmotor2.html
see what you think?
http://users.abilene.com/~dkelly/hotrod/newmotor2.html
see what you think?
Senior User
Joined: Dec 2002
Posts: 251
Likes: 0
From: Phoenix USA
351C 4V heads
Fordmech,
I did this with several smallblock heads years ago, and had real good luck with it. But you have to understand my application was for drag racing, a little less racing time then you have. I took mine flush with the roof of the port, guide and all, with no problems. I might recomend to only shape the intakes to improve the flow, those valve heads are big and may need the support. If you're not already using them a set of port plates for the exhaust might help the flow on that side also.
Joe
I did this with several smallblock heads years ago, and had real good luck with it. But you have to understand my application was for drag racing, a little less racing time then you have. I took mine flush with the roof of the port, guide and all, with no problems. I might recomend to only shape the intakes to improve the flow, those valve heads are big and may need the support. If you're not already using them a set of port plates for the exhaust might help the flow on that side also.
Joe
