Compatibility

Sounds better to start with a factory spd roller car then.
if it's your goal to have a four-speed I would just start collecting things as you find them. There's a bell housing for 250 and see if you can get him to throw in the throw out bearing fork and the boot. See if you can find a shifter and linkage. They sell floor humps aftermarket I'm pretty sure that you can still find them for 75 bucks or so. Start looking for the 4 speed pedals they both right in no problem. You can slowly gradually get the things and when you see a good deal on the correct force-feed grab that. Unless you have it like that then go ahead and call Brewers and order the whole damn thing. either way it's going to cost a little bit but in the end you won't regret one dime...