Saw Mill If you make your HEI distributor the same mimensions as your GMC take-out it will work,watch for interferance where the big HEI is close up on the side of your 270. I use the coil in the cap type for simplicity and so you could have a spare under the seat for the road. I think that on disassembly you'll find sludge on the HEI shaft makes it hard to get apart,once it's out you can clean it up. Then do your magic,once running it's great. Those GM engineers are pretty sharp !!