I'm building gen V 502mag EFI for more power and change mefi to holley terminator X. Also change distributor to Holley dual sync so I can make sequential injection mode. Hope that help idle quality with bigger roller cam.
Problem is that HEI style cap is so high that it will not fit under upper intake. Does any manufacturer make lower profile cap where spark wire connectors are pointed sideways?
Another option is machine spacer plates below upper intake, but it's not good choice because I already modify lower intake ports.
Lowering the distributor is quite complicated.

personally,I'd cut the upper manifold so the distr. cap fits and then weld up the hole.thats if you can't find a lower cap for that distr.

Change back to Delco EST

can you run the crab style cap with this distributor ??

I don't know if this would work for you, https://www.jegs.com/i/MSD/121/8541/...All%20Products

I just paint parts, welding is not first choice. And upper intake may twist from welding.

I found crab cab also in internet, but it looks so low that it won't fit to hei distributor. Does anybody know the truth? I have one MSD billet hei distributor cap and it fit well to Holley distributor. Soif crab cap fit MSD HEI, it should solve problem

Id call Holley Tech and tell them your issue and see if they have an answer....... I think there is a low profile HEI cap out there but dont have a part #

My worse english doesn't allow that but maybe I will mail them. Tried first here because somebody else may have had same problem before.

that looks to be a good 3/8's of an inch from clearing

1/2" at minium so wires can pull off without remove plenum. water cut spacer flanges do the job but crab cap is most simple way if it fit