I moved the engine forwrd on my K5 when I did the swap so the T-case could stay put. With
no lift I had lots of clearance for the front diff. I used the AA output shaft and stock adapter from the TH350.

The 700R is 1-3/4" longer than the Th350. I moved the engine crossmember ahead accordingly.
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72' K5 Blazer 4x4 350TBI/700R4/NP205 3/4 ton diffs. Daily driver. SOLD
69' Beaumont 388/700R4 11.70@116
77' Bronco, Wife's mall cruiser/poser 4x4. Capable but too pretty to go offroad.