Posted by Chris on January 07, 1999 at 04:50:33:
In Reply to: 351modified into 1977mav posted by tyler hendrickson on December 17, 1998 at 22:26:41:
First of all, the "M" motors are small blocks.
They have the same bore spacing as "Windsor" motors. That's why you can swap "Cleveland" heads to "Windsor" blocks. Second, it would be difficult to swap in because of the shock towers. But not impossible! Modify the shock towers like when going with the other 351's (probly cut off as much as you can). You can also use the factory
"M" series motor mounts. Also look for mid '70's
mid-size cars (Torino's) with 351M motors. They will have C4's. The hardest part (or expensive) is
having custom headers made. Third, don't waste your time buiding the 351. Go with the 400 !!
Also, I would suggest using the 4V heads (the 400 will love them - we've done it). If you are stuck with using the open chamber heads (2 or 4V), use a set of Keith Black flat top pistons (# KB177)
and bush the 400 rods for the smaller pins. This will give around 9.5-10:1 comp. I could go on about modifing these motors but I'll stop here.
If at all possible, try to use at least 2" pri. tube headers. Remember, for the most part, the "M" motors are "Clevelands".