fighting a converter to go all the way in drops in my old trans fine the new replacement not happening splines look good what am i missing

Lockup trans? Converter that’s not?

Iirc there is one spline different between lockup and non

What's your install technique? assuming you have the correct converter...

Which year trans and converter and which type trans?
None of the 727 converters I've installed went in easy
I stand the tranny up on its tail shaft and then align the pump drive teeth straight up and down and then try to install the converter with the pump drive slots aligned with the teeth on the pump
Even then I usually have to rotate the converter back and forth a 1/4 to 1/3 turn to get it to drop down both ways, onto the input drive shaft teeth and then down onto the pump lugs
I have found that the race converters with the 7/16 holes in the lugs need to be down right at 3/4 inch from the front of the bell housing face to the face of the lugs, the converter flex plate side
Good luck, you can do this

dynamic converter 727 bb trans not sure of the year same number splines 24 on the input shaft 27 on the pump drive ive got the trans in a metal can facing up as usual just cant seem to get this beeotch to drop in just wondering if the trans has an issue i have seen that pre 1967 was different

just when your ready to give up it will drop right in

I've had a couple that fought like crazy for no apparent reason...
I don't stand them up anymore...I got my fingers pinched pretty good once when it finally decided to "drop" in...

If still vertical - take a clean small screw driver and carefully go past the pump seal and make sure the rotors are free to turn.

I’ve seen them get stuck and if they won’t move and the inner rotor isn’t centered you won’t be able to get the converter in.

i made a tool years ago, from an old converter, to line up the the pump gears. makes it a little easier to get the converter to seat. the monroe book shows this tool on page 79.

Last one I did was fighting so took a magic marker and marked the pump tang location on the converter....it went right in then.

Lift on the converter pilot slightly with one hand while pushing in and spinning the converter with the other hand.
Doug

thanks for all the input believe me i tried them all dont know why but just like bone fish said when i was ready to give up the sum beech dropped in thanks kenny

I did a 73 trans this summer, got a new vert. Would not go in (lugs aligned). got another input and reaction support, stuck them in the vert and turned a couple times till input slid in, vert went right in the trans first try. Never had that problem before.