E6SE

I'm sure you can get some good HP numbers if they are ported. The E7 heads flow better then the E6's. 25hp worth. I'm sure you can get the E6's to flow better then the E7's so you are looking at some pretty good gains.

Here's the problem....your pistons (if still stock) don't have any valve reliefs cut into them. So, if you port them (which i assume would include bigger valves, otherwise you wouldn't gain much if any kind of hp gains if you open up the runners but don't change valve size to match) you're going to run into piston-to-valve clearance issues. In fact i'm not 100% sure (because i've never heard of someone going from E7s to E6s) but i don't even think you can run E7s on an '86 because they even have bigger valves. I guess you could always notch the pistons but i never was fond of that idea...taking away piston material seems like a bad idea to me.

should be the same size valve in the e6 and e7 i have both set laying around look the same to me but the e6 have smaller intake ports.would be nice if you could find a set of 315w head to put on it, the how ever do have bigger valves.
There is nothing wrong with fly cuting piston either.