i have dart pro1 heads, angle plug, and im having a clearance issue with plugs on cylinders 7 and 8, the boots are going to be touching the headers, which are SLP 1 3/4 coated. I need a set of shorty plugs, but the only shorty plugs i can find are the accel ones and they are the wrong thread type. Is there another out there somewhere? I really dont want to dimple a set of 600$ headers.

you could try just regular copper core bosch's. I have the 1-3/4 SLP's and thats what ive been using (albeit with stock heads not angle plug like you). They are a little shorter than regular AC Delcos.

Autozone sells em.

I have the SLP headers on my Bowtie heads, angle plugs (left side only). Much to my dismay, I discovered that the #5 and #7 spark plugs needed to be shorties when I swapped the heads. luckily the Accel ones worked.

on the passenger side, no such luck, shorty plugs weren't short enough. I had to replace the SLP header with Hooker shorties. that was an unplanned for unbudgeted financial emergency. talk about "work stoppage".

so now my motor's got 2 kinds of spark plugs, and 2 different brands of headers, Hookers on the right, SLP's on the left. but it sure runs fine.

well i hope i dont have to go that route, accell shortiew have the wrong length thread for the dart heads, so i cant use them, i hopw i can find something, id rather not have to buy another set of headers.

I guess It may help to know what type of plug wires you are using. Some of them are so big(Taylor & Jacobs) or the plug boot angle larger than 90 degs, that I'm not surprised that they hit the header tubes. As for plug type, I'm un-familiar with the type of plug seat that Dart uses on their Pro1 heads. Gasket or taper. If its gasket, try autolite 3924 that is what I use with a set of MSD wires. I have never had a clearance problem with them.