I have a 90 d150. I just built a 360 for it and bought a Hughes converter for the trans. The trans is a A904la but I'm not sure if its the stock one or not. The Hughes converter fits in the trans but will not lock in. the slot on the shaft on the new converter is 3/8 wide. The original converter slots are 9/16. When I ordered this converter I ordered it for a 904 so it should fit and I called the summit tech guys and they said that there's no way it. Won't fit. I've put many of these in but can't seem to get this one in. Any help?

Hi
Unless your transmission is an A-998, it has to fit ! make sure......(guess you already did !)

Dan

904 converter will fit 904, 998, and 999 trans mission as they use the same TQ...

now is the transmission a later 80s lockup transmission then..the input shaft is different...

look on the pan rail of the transmission ...there is a number that starts with PK

post that...

is the first inch or so of the input shaft smooth or does it have splines all the way? if it is smooth you have a lockup trans. converter you have will not work if the trans is a lockup. i am willing to bet being a 90 model that you have a lockup transmission.

some time in the 90s the pump lugs changed to the flatson the TC snout.

those will not fit in a no-lock up or lock up trans that have the notched pump lugs in the TC snout.

the input shaft will either be a smooth end about 1" for the lock up.

the no lock up will have splines all the way to end of input shaft.

you will also need the correct weight on the TC for the 360engine.

if it is lock-up and you want non-lock up, you can block the LU valve and it will shift but not LU the TC.

I found that the pan rail #s can be very helpful but not always correct when checking them. I have found lots of rebuilt units that where changed/repaierd/moded in it liftime as they get older.

The narrower drive slots are typical of aftermarket converters and shouldn't cause a problem installing it. (the slots are still wider than the drive tangs on the pump).

Mismatch of the input shaft splines (lockup/non-lockup) will prevent installation as will a '96 or later trans with the flat-side drive. Shine a flashlight into the front seal on the trans and look for the two drive tangs.