As far as i know YES, any pre 98ish mpi with mefi1 or 2 has a smaller feed hole to # 7 injector. Btw, Its amazing how much flow the mefi3/gen 6 stock maggeti/ marelli njectors flow when they are tested. Its funny how hp500efis flow 36/38 lbs per hr but the late 454/502 injectors are around 46 lb so at .5 bsfc can support 750hp easily with a little fuel pressure increase where the older 502/454/500efis can barely support 600hp.

Yeah either the price has went up quite a bit since I bought mine 4 yrs ago or I have a bad memory. I thought I paid $1100 total.

Ok so how does the autotune feature work, if there are all kinds of setups can it really fine tune??

About this boat:

http://www.boattrader.com/listing/20...100-102878742/

it has mfi and the prochargers , so what would be needed for this boat? Just to change the computer to the holley then splice the 5 wires into the new computer? and it autounes?

So what injectors do you recommend for a 509 0r 502 with supercharger, heads, cam etc , Mer. 454 injectors or another after market option?

Injectors sized for the HP you are targeting, accounting for 80% duty cycle limits and what I consider normal/nominal 42 psi fuel rail pressure. Brand would depend on what style are currently installed.

Trash answered it perfectly, IF your going to make any kind of real hp buy the appropriate sized injectors that physically fit your intake. Easy math: say 800hp goal, at 3 bar rail pressure and .50bsfc a example: 60 lb x 8= 480 lbs, at .5 bsfc will support 960 hp. 80% of that is 780. At .55 that goes down, go on rc or marren injection and calculate flow of injector at a higher fuel pressure they will support about 15 to 25% more. If buying new size them appropriate and use fuel tables for all the tuning. If your injectors are close and you already own them than consider raising fuel pressure under boost, smitty