The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 70 4x4 suburban- wanting to go big block

B. W. · 03-15-2017, 10:20 AM

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.

03-15-2017, 10:20 AM	#3
B. W. Registered User Join Date: Nov 2014 Location: Bigfork, Montana Posts: 1,137	Re: 70 4x4 suburban- wanting to go big block 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.