Spark Plug questions.....

Okay, so I'm building this 283 for my 88. It's mostly together and I have a question. I looked up the spark plugs for a 63 283, they give me a number AP86. That's the block a 63. The heads are a late 70's 305 heads w/60cc chambers. I am running a stock quadrajet off of a 71 Chevelle 350 auto. The distributor is off a late 70 early 80. It an hei dist.

If I run the engine as a 63, it takes the ap86
If I run the engine as a 70's model, it take the ap26
If I run it as an 88 it take an ap24.

WHAT PLUG SHOULD I USE AND WILL IT MAKE A DIFFERENCE??

I am leaning toward the ap26 because I am using 78 305 heads

When I built an engine for one of my vehicles about 20 years ago I was in a similar situation. I had a 400 block from 1970 with 1967 327 heads and a Carter 4bbl carb with an Edelbrock intake with HEI. The guy who was helping me build the engine told me to use the plugs that were meant for the heads, but gap them for the HEI. That combination worked great and I have used it since then without any problems.

That sounds good. I was actually leaning toward using what was for the heads. So at least I have one simple thing down.... Gotta take the damn oil pan back off now, forgot to put the oil pump drive retainer on.