Running "A" Heads on a 70' 455 block
#1
Running "A" Heads on a 70' 455 block
I want to build one of the 455's I got. Out of the sets of heads I have, 2 "C"'s (small valve) and "B" (needs seats), "A"'s are the only ones I could bolt on without much rework. I did a port and polish job years ago on them. Now after some research and reading the "Engine Modification and Tuning Guide", I realize the different lifter bank angles and that the pushrod holes need to be opened up to .562 (9/16"). The holes now are roughly .5 (1/2"). I don't think I could open up the holes that much without busting through the intake port wall.
Does anyone have any experience using "A" heads on later blocks. Can you get away with maybe boring out the bottom half of the hole? Maybe it's a trial and error thing. I really don't think I could bore out the whole hole. Maybe a thinner push rod. Thanks.
Dan
Does anyone have any experience using "A" heads on later blocks. Can you get away with maybe boring out the bottom half of the hole? Maybe it's a trial and error thing. I really don't think I could bore out the whole hole. Maybe a thinner push rod. Thanks.
Dan
Last edited by 67Olds442X2; May 12th, 2010 at 09:20 AM. Reason: Lifter angle not bank angle
#2
I want to build one of the 455's I got. Out of the sets of heads I have, 2 "C"'s (small valve) and "B" (needs seats), "A"'s are the only ones I could bolt on without much rework. I did a port and polish job years ago on them. Now after some research and reading the "Engine Modification and Tuning Guide", I realize the different lifter bank angles and that the pushrod holes need to be opened up to .562 (9/16"). The holes now are roughly .5 (1/2"). I don't think I could open up the holes that much without busting through the intake port wall.
Does anyone have any experience using "A" heads on later blocks. Can you get away with maybe boring out the bottom half of the hole? Maybe it's a trial and error thing. I really don't think I could bore out the whole hole. Maybe a thinner push rod. Thanks.
Dan
Does anyone have any experience using "A" heads on later blocks. Can you get away with maybe boring out the bottom half of the hole? Maybe it's a trial and error thing. I really don't think I could bore out the whole hole. Maybe a thinner push rod. Thanks.
Dan
#3
Thanks for the reply.
I'll try a dry fit first. To be honest, I edited my original post by removing some content, but I had run these heads on an "E" block many years ago cause I didn't know the difference. Didn't run it long so can't predict what the actual outcome would be but I didn't notice anything after the short time running it, no damage or signs of rubbing. Since this is a different block and about 25 years since then, I'll check it out first, maybe I'll get lucky.
I'll try a dry fit first. To be honest, I edited my original post by removing some content, but I had run these heads on an "E" block many years ago cause I didn't know the difference. Didn't run it long so can't predict what the actual outcome would be but I didn't notice anything after the short time running it, no damage or signs of rubbing. Since this is a different block and about 25 years since then, I'll check it out first, maybe I'll get lucky.
Thread
Thread Starter
Forum
Replies
Last Post
Carl, uk
Small Blocks
22
March 13th, 2014 05:43 AM
ut442
Big Blocks
5
March 9th, 2012 11:57 AM
joepenoso
General Discussion
15
November 7th, 2011 07:18 AM
81 regency
Parts For Sale
0
April 21st, 2011 06:18 PM