i would go with dsm 450cc injectors. and your lucky you have a d-series don't worry about a rebuild just get a new block post up in the for sale forum you need a d series block and you don't want to spend more than 75 i bet you get 15 people offering you a block buy three or four of them and call it a day just keep swaping them in when you blow one and it will only cost you a few hundred for the block's free labor, and i bet those block's will last a few month's also you will get to try new block to see what work's best so for, so for 3-400 you get 1year+ sounds good to me. the best d series block's d16a6(crx si block), 1.5 vx motor(biggest d series rods), and then the y8. use your oil pump since it flows more than other d series pump.