since your doing your kit yourself, 5" off the frame for the front mounts and you dont have to modify the cab floor. 3.5" like I have and you have to build a trans tunnel. between 1.5" and 3.5" and you are building a trans tunnel and driveshaft tunnel.

Below 1.5" and you are into new sheetmetal for the back of the cab. The following pic is with 1.5" of spacer between the frame and cab (a piece of 2 x 4)

http://good-times.webshots.com/photo/2917645630101989507lTpKbX

here is a link to my swap that has other useful links https://www.stovebolt.com/ubbthread...;Main=58105&Number=421710#Post421710

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me