Does anybody make 4 bolt main caps?
Does anybody make 4 bolt main caps?
Pro-Gram Engineering. http://www.pro-gram.com/
I believe it's a 401 mod, as the main webs are thinner on the 304/360 blocks and don't have enough meat to drill bolt holes.
Remember that the block will also have to be line bored after installing the caps.
Bob
tufcj
1969 AMX
1967 Rambler Rogue
If you need a tool and don't buy it...
you'll eventually pay for it...
and not have it.
Henry Ford
Hmmm, I thought that there were thicker casted 360 blocks that would support this mod?Originally Posted by tufcj
Yup, sure do... Standard practice.Originally Posted by tufcj
Yep but those blocks are very hard to come by, I think they were cast for Trans Am racing.Originally Posted by fifesjeep
1979 Jeep CJ-7 401 AMC, GMC 6-71 Blower 10% overdrive, Bugcatcher with electronic fuel injection and a little N2O for fun, all self built. (this supercharger stuff is easy)
Cool, makes sense. I'd be nice to stumble upon one in good shape.Originally Posted by Blown7
The one at 74 Javelin was good enough. I still wonder why they did not make more in any of those ever.
Everyone, take one... repo trucks for sale
The factory service blocks were basically a blank with slightly heavier castings, it was up to the final user what they were at the machine shop (304/360) IIRC
My first post here. AMC 1970 390 and all 401's will accommodate 4-bolt mains. The "service block" is as described above. It has the same bottom end as the late 390 and all year 401 and was a 4.08" bore 360 cylinders with enough material in the cylinder bores for the service department to bore to 4.165" 390 / 401 specs if required. There were some smaller 290 engine blocks made with 4-bolt provisions but that was a Trans-Am race block and very rare indeed.
Milidon and Pro-Gram Engineering make excellent 4-bolt main caps. Milidon availability can be iffy, Pro-Gram will get them to you in a reasonable amount of time. You can buy the three middle caps with 4-bolt. Pro-Gram also offers billet #1 & #5 caps but those are 2-bolt. Just keeps the billet theme going. I have all 5 on my '70 390 race engine. You will need to line bore / hone ANY block if you change the caps (even if factory standard caps). Caps are married to the bore.