Check the ratio of each gear by engaging each gear and count the input shat revolutions needed to turn the output shaft on revolution wrench scope
if the input shaft turns 2.5 and tiny bit more it is a 2.66 low gear ratio pre 1971 340 tranny, if it turns a little over 3 full turns it has the 3.08 first gear found in the 273 and 318 a body 4 speed cars. scope up
If it turns a less than 2.5 turns in low gear it is one of the 1971 and later close ratio 2.42 low gear ratio trannies shruggy

I like and use the 3.08 low gear tyranny's on any street car I can get one for, BB or SB up

Last edited by Cab_Burge; 02/18/24 09:49 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)