What is the best engine you can put in your 93 Honda Del Sol?

If you got the money, go for a new J30A5 engine. it is possible to put in that beast in a little Honda. making 230Hp and 210Lb-of torque.

DSR.

A cheaper and easier to fit engine is the B18C from the Integra GSR. 178HO and 128ft-lb of torque. If you use the transmission as well it will all fit very easily and won't even require any special tuning if you use the ECU for it as well.

You can get a long block (tranny+block+head) for around $1600-$2000 from sites like hmotors.