BU602 1957-1963 Buick 401/425 Nailhead (w/ 2.90" crank flange) to Chevy Automatic Transmission


Materials Included:

(1) Adapter Plate - Buick Nailhead to Chevy
(1) Crank Adapter-Inner
(1) Crank Adapter-Outer
(1) Torque Converter Drive Plate
(1) Flexplate - Small Center-Balanced Flexplate
(1) 166W Tooth Ring Gear
(1) Balance Weight - Buick-401/425 to Chevy Auto. Balanced FP
(6) SHCS 7/16-20 x 3
(4) SHCS 7/16-14 x 1-3/4
(2) SHCS 7/16-14 x 1-1/4
(6) 7/16-20 x 3/4 Flexplate Bolts
(2) Dowel Pin .621 x 1
(5) HCS 3/8-16 x 1-1/4 YZ8
(3) 7/16 H Extra Thick Washer
(3) 7/16 Flat Washer


Are you planning on using a modern a GM 4L60E, 4L65E, and 4L70E (2008 and earlier only) or GM 4L80E and 4L85E transmission with this kit? By adding a US Shift Quick 4 stand-alone transmission controller you will save $100 dollars off of the cost of your Speed Gems adapter kit. 

We have additional options from US Shift. Please give us a call if you're not seeing what you need!

*Matching our adapter kits with your engine can be tricky. If you are unsure of which kit to purchase for your engine, please call customer service at (763) 767-4480. Speed Gems is not responsible for return shipping costs of mismatched kits.

Installation Instructions

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