Uploaded January 2021 | Updated September 2026, 30 minutes ago

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In Pt.2 of Zac's quest for earth shattering torque in his 1978 k5 GMC Jimmy, the 572ci Big block is assembled from pan to intake and prepped for its Dyno session. Engine builder, Jacob Villemain from Smeding Performance gives us an in depth run down on all of the components used in the motor along with detailed tips throughout the assembly process. This engine features a Dart Big M engine block, custom crank and rods by Smeding, JE Pistons, billet core custom ground hydraulic roller cam by Comp Cams, AFR 335 Heads, Edlebrock Victor Jr. Intake, and A Holley Sniper X-Flow EFI system. Its safe to say this thing is gonna be a handful on and off the road.

Catch up on the k5 build here:
572 Swap Pt.1 - youtu.be/5mkZP3v41I8
4l85e/NP205 swap - youtu.be/mqtLIdfi7HA
Painless Wiring harness install - youtu.be/vDuvZ5BCBmY
Vintage Air front runner kit - youtu.be/pue_yBMkNYM
Vintage Air A/C install - youtu.be/6RTem2G9MZ0
Currie axle & diff rebuild - youtu.be/6KDTKy7CwBM

Special Thanks:
@smedingperformance
@thatengineguy
@holleyperformance
@dartmachinery
@AFR_Heads
@CompCamsOfficial
@gearstarpro
@painlesswiring
@vintageair_
@currieenterprises
@thermotec
@driveshaftpro