I have been collecting parts to convert to fuel injection for a while, have 2 single plane style intakes with throttle bodies and injectors, 1 Cutler and 1 Accel. I just acquired an MSD 2345 pro billet distributor with a cam sync and mag pickup (whats the odds of finding 1 of those at a tiny swap meet for dirt?). Car is my 72 Chevelle with fresh 454, hyd roller. Current ignition is a large cap HEI, no module, just the pickup firing an MSD 6T box with an Accel coil mounted on the cap. I think I need the 550-604 ECU and harness but unsure on ignition harness for the MSD dist. I think I can run sequential with that dist? I think I want to still use the MSD 6T box. Recommendations for a coil? Anything else? Have an Aeromotive pump, thinking of using the mechanical pump to feed a small surge tank mounted on the front of the engine, which would then feed the Aeromotive pump. TIA, Jim.

Jim,

Your correct, the HP ECU & Harness Kit - 550-604 is the best option for your application. The injector harness is designed for "over the rail" fittment but, works ok under the plenum aswell. There isn't a "plug n play" ignition adapter harness for use with the MSD distributor but, it should be an easy build. It don't care much for the MSD dual sync due to the unit using magnetic pickup for cam/crank signals which are more succpetible to noise. Doug F may have some input on this.

The other options you can consider are I/O harness. This is a metripac connector/leads designed to plug into the I/O connector on the main harness. This is what you would use for electric fan(s) etc. Oil and Fuel pressure transducers are also available for monitoring/datalogging and saftey triggering. The harness is already prewired for the transducer, you just need to purchase them and plug in.

Yes, you can continue to use your current MSD igntion. You can use any equivalent coil to the version your running. We've had good luck with MSD Blaster and HVC coils.

Thank you Dennis. Can someone explain the "noise" problem with the mag pickup? I shouldn't order an ignition harness, just plan on making one up? Does the ECU come with instructions for this? I have a small cap HEI and probably a large cap computer controlled HEI as well, if either of these woukd work better. Aren't HEI's mag pickup also? Thanks, Jim.

Doug? Anybody?

The mag pickup for crank (e.g traditional HEI) isn't an issue. Where I'm concerned is with the Cam Sync is also mag and some secondary igntion noise can affect it. I know Doug F did some testing with the MSD...I think the results weren't as good as the Hall Effect dual sync. This is why most systems today use Hall Effect vs Magnetic Triggering.

The HP EFI has complete wiring diagrams for all types of ignition inputs...yes you can easily make one up. They don't "instruct you" however....I can walk you through which get pinned where.

Small Cap or Large cap HEI are fine but, you will not have a cam sync and therefore only run batch, bank/bank or paired injection strategy. Sequential requires the cam sync.

I don't care to have any mag pickup in the distributor. A hall effect, like a FAST distributor has is 10x better from a noise susectability standpoint. That being said, if you use shielded/grounded cable into the distributor, you should be ok with the HP for what you are doing with the mag pickup, assuming the distributor is in decent shape.

Thanks Doug, distributor appears to be new, so I'll try it. If it's a problem, I'll change to a Fast (or figure out how to change this one to hall effect). So I'm guessing I'll need the 558-306 ignition harness? Jim.

Correct, the 558-306 is your best bet.