I have read somewhere that the 2 motor mounts( 1 short and 1 long)you have now. Will be no good to you, well thats half true. You will need 2 of the long ones. This will give you the set up for an 8 cyl....

I am pulling this from the back of my mind and I am offering this info and stating "Don't quote me on this tho'"

<center><img src="http://www.angelfire.com/ns/2xcapers/images/GMC_910_avatar.gif" alt="3 speed burnout">

Turn them Tires, so ya can
smoke 'em and choke 'em

[Linked Image from angelfire.com]
Vic... '65 GMC 910