just bought a 90 dx 5spd and its rough, im going to do a full resto on it but i wanna first ask what engine/ trany combos i can swap into it with out replacing axels etc. , im not going to boost it, i dont have all the money in the world to blow on it like everyone else im sure, a bang for your buck swap would be nice, thanks

 

I would go for the D16Z6.
Great upgrade now and gives you lots of room for future upgrades.
It bolts right up to your existing transmission so you don't change axles.
You can grab an 88~91 Si transmission to help out on performance as well - still keeping your stock axles.

 

I would agree with the Z6 or a Y8. They are light enough where you'll feel the added oomph and it will make it somewhat entertaining to drive.