can you switch a 7 pin HEI module in place of a 4 pin?

I am starting to resume gathering parts to add TBI and a MegaSquirt to my oddfire dauntless. My GM HEI runs great but it's a 4 pin HEI module. Can I simply swap in a 7 pin module that is made for an in cap coil so I can use the MS 2 and control the ignition with it. Or would it be better to just go with the MS 1 and control only fuel?

The TBI unit I have is from a 94 astro van 4.3 and doesn't appear to have a stepper motor on it.

Thanks for any and all.

 

Ok, according to what little I can find on the web about this, I think that I can. I will need to tack weld the mechanical advance and get rid of the condensor. and mount the 7 pin on the fender or firewall.

The Tach out pin on both the 4 pin Module and the 7 pin module will work well as trigger.

If anyone knows different please let me know.

 

Pretty sure there's a section on binderbulletin about using the 7-pin module for spark control. http://www.binderbulletin.org/forums/showthread.php?t=46961 This says you need to freeze the mechanical advance - I presume that's because the 7-pin module supplies the advance electronically.

I think there's something on the CustomEFIs site too, but I'll have to wait till I get home to look at that.

 

Condensor? Not a RFI suppressor?

 

Tim, I figured you would be the one to answer this.

From what I can tell from the sites you listed and from another one I found (junkyard tbi) your correct. lock the mech advance ( i have already locked the vacuum advance (removed the canister and put a machine screw through the plate.

Yep, the whole reason I am looking into this is to use the megasquirt to control the ignition also.

It's condenser. But I suppose it could be for RF? see attached images