Playing the long game!

[YBNORML]

Originally Posted by 68Gold/white

That gear is perfect. A Th350 is a bolt in deal. Same length, shifter linkage is slightly different, you'd need the kick down cable bracket for the carb and to connect to carb. I performed this swap on my 67 Bel Air years ago, made a huge difference in drive-ability.
I hedging that your engine may be a 283. The 283's and 327's had the smaller 2G 2 barrel carbs on them. They act like a governor at higher RPM's. I built a 283 for my Bel Air back in the 80's. Thought I could get some great MPG numbers. 20 MPG was my best.
The block I.D. is behind the driver side head. That will tell you what you have.
I hope it's a 327, you could stroke it to a 383, nobody would know
I have other ideas...

Yeah, I know where the casting info is. Work has just been so busy it took me two weeks just to get my wheels on the trucks after having them mounted and balanced!! But, I guess that's a good problem to have.

It sounds like you have quite a bit experience with these, I'll be picking your brain when the time comes.