904 rebuild

I'm thinking of rebuilding a trans for my swinger pretty soon. I have a 727 in it now that I kinda messed up not getting my shift linkage adjusted correctly and fast enough. It doesn't take long to smoke one of these things from what I call tell. It slips and almost acts like its starving for fluid when it's cold, it does much better after it warms up. The guy I got it from said he had rebuilt it and it has a "spragless" converter in it. Anyway I have a 904 sitting in my garage that shifted fine behind the 318 I had in the car previously. I've read that they're not real complicated so I'm thinking of building it and buying a new converter for it. It'll go behind a 340 with j heads, air gap and a Mopar purple cam, dougs headers and a 4:10 sure trac. With all that said I'm looking for suggestions on what kit is recommended. Can't go wild on the cost of this but don't want to skimp out on it either. Any suggestions or tips.