Been asked before: MM

[arkracing]

Well I have a question that i'm sure has been asked before...but I searched for it and can't seem to find the answer that I need:

I have a 6cly truck that will get a V-8. I know that the V-8 will mount to the 6cly stands - but may have some clearance problems with an HEI dizzy.

so the question is...on a stock V-8 truck how much further foward are the Motor mount stands than in a 6cly truck.
I noticed that there is another bolt hole further foward on the top side of the frame about 2.5" infront of the first bolt of the 6cly mount...
do i just move the mount to that position and drill a new bottom hole?
or do i have to drill some new top holes too? - and if so..what distance from the stock 6cyl holes?

Thanks guys