70 4x4 suburban- wanting to go big block

[STP67-72]

I have a local guy wanting to put a bigblock in his 4x4 suburban. I was told to move engine forward for firewall clearance ?? Gives room for valve covers and HEI clearance ?? Will stock small block mounts work. It's a 350- granny 4 speed. Going 454 , t-400 etc. thanks for any and all help.

[kwmech]

Much easier to pull the engine forward to the next set of bolt holes in the frame (You only have to drill one side) than pounding the firewall for the valve cover and the distributor if you've got an HEI. I have not put a big block in, but I know there will be an issue with the big block oil pan hitting the factory x-member with the small block cushions. You may want to try or measure the 2wd big block cushions. I know they are thicker.

[B. W.]

kwmech is spot on, when you move the engine forward you also need to check clearance between the engine cross member & the front axle. If springs are stock (and worn out) you may not have enough clearance. Also, with 350 mounts you will probably have clearance issues on the passenger frame rail with the exhaust manifold. Headers may solve this (or may make it worse.) I have have not done one but a friend of mine has a 71 K20 that he put a BB in. He did not change the mounts & had to notch the pass frame rail.

[ajviper]

Replied in your original thread up in the Suburban section.