This sweet GTO came in for a 5 speed manual transmission swap. It had a tired 326 that had replaced the original big block at some point. The owner wanted to keep it Pontiac. When we  and the 326 was on its very last legs. He sourced a 6.6 Pontiac to replace it with.

Surprisingly, even though Pontiacs use the "same" block for big and small blocks there were changes between the 60s and 70s that necessitated some changes to replace the vintage 326 with the 70s era 6.6. The swap required engine mount adapters (that then had to be modified), flywheel, pilot bearing, and some other seemingly minor changes that had outsized effects on the transmission swap.

The 326 checked good on the bellhousing runout, but the 6.6 required offset dowels and some patience to get right. Correct bellhousing runout is CRUCIAL to smooth shifting and transmission life.

We also cleaned up some of the wiring. The harness in the car is still original, and it had seen better days. We were happy to fix a couple of the more glaring problems.

The GTO turned out great, and the car is once again a Pontiac powered, manual transmission GTO. Though the 5 speed is not historically correct, it will definitely make highway cruising more fun!

We'll be seeing it again this summer after the clutch is broken in for some performance tuning with the new Brawler carburetor. Thanks Mark!