Doing it right -need some advice

Interesting, ok. Well I could bolt up the flywheel and bellhousing and get th cranking compression.

Keep in mind this is Passon OD gear set. Not factory ratios. Here they are.

View attachment 1715855323

Nice ratios, certainly better than the Mopar-OD box! .The new numbers become;
Starter of 2.66 x 4.10= 10.91 Excellent
Second of 1.59 x 4.10=6.52, a reasonable second for a 360, but only ho-hum for a low-pressure 340.
And 60=4870 with 27s
Cruise gear of .80 x 4.10=3.28s ; So 65=2650 with 27s, a lil high but easier to make adequate cruise-timing with.
The gear ratios are a nice progressive 1-2-3 with a short Fourth, perfect for a 340;
2.66-1.59-1.00-.80od with splits of .598-.629- .80.. The Commando box, which I really like is;
3.09-1.92-1.40-1.00 with splits of .621-.729-.714
I think yur gonna like that Passon box. I'm looking forward to seeing how it works out for you