Thats what I did, 23 on the 1.5 and 21 on the other, there was a 1.36 drive made for big blocks before the bravo was made. I'm within a few hundred rpm now, maxing out @ 4500, found a perfect pre alpha 1.5 for $700 upper and lower with trim cyls I may pick up next week

ok, the 1.36 ALPHA- not pre alpha was 87 only. the TRS discontinued in 86, Bravo started in 88. unless yours are really alphas and u think they are pre alphas. neither of us can post pics. u have any pics of your drives u could email me? I will be able to tell at a glance. I think u should pass on any more pre alphas, no matter how nice. the spring pin in the upper end of vert drive shaft weakens the shaft. that is where they snap. [email protected]

The boat has one 1.5 pre alpha (round cav plate) and one 1.36 alpha, so to get rid of the pre alpha, I would have to buy 2 complete drives, not going to happen

i have a few mr alphas that i can part with..,,fyi,,you can bolt a gen one alpha in its place..

ok, everything I read says the gear ratio is changed with the upper. all lowers the same 20-22 tooth gearsets. so, find a whole 1.5 alpha and use the upper to regear the 1.32 one and have a spare lower for the pair...