[Mister Pontiac]

Today was a fun day... first fire up of the (new) 455 in the GT!

As with most of my projects, it took me longer than I wanted to get here, but the 455 is finally installed, cam break-in is complete, and I put about 100 miles of driving on it today. Tomorrow I hope to get in another 100 or so miles of driving. Wow, what an improvement over the tired 350 2bbl.


Quick refresher... I built this 1972 vintage 455 bone stock. Aside from a 0.030" overbore, I simply freshened up the bottom end (stock except for ARP rod bolts and forged pistons), 067 cam, and even went with the odd duck (unloved?) 7L5 heads (same functionality as the 7M5). It comes in right at 8:1, and ran all day without a hint of detonation on 91 octane (temp in the 80's & vacuum advance operational). I imagine I will be able to run 87 once things are all settled in.

It idles dead smooth, and pulls like a freight train from the basement to about 3000 RPM, right where I want it. It rarely sees anything more than that as the GT is my runaround daily driver. I didn't want to build anything more. The goal was to build a mild, low RPM torque engine for daily duties on pump gas with the A/C on. Also, I wanted to keep it as accurate as I could to a correct 1972 455 factory build. I think I've hit exactly what I was aiming at.

Anyway, hope my swap and fun day encourages others to keep after their projects too. Sure is satisfying to enjoy the fruits of your 'Pontiac' labors!

Just thought I'd share the update, and attach a few before/after pics for you guys.

Enjoy!