Thread: Butterfingers

Tweet

I was polishing my '86 5.0 "swirl" heads, and once I'd ground off the emissions nubs from the exhaust ports, I decided to open up the exhaust ports slightly because, well, they're tiny. I had about another 3/16" of room to the gasket in every direction. Well, one thing led to another, and before I knew it I'd opened them clear out to the gasket scribes. Stepping back to look at it, all I can think is, "Wow. That's really big."

I can't really undo it and I'm not sure I want to; I just can't find any references to gasket-matching the exhaust ports except on sport-compact-buildup boards, and one mention on these boards where a guy said he killed his low end by opening the exhaust and intake ports too much.

The intake ports have been polished but haven't been ported. They're already within 1/16" of the gasket on all sides.

I'll be running around 9:1 compression on a dual-quad 289 tunnel ram intake with full-length 1 5/8" headers and a custom-ground cam of about .475-.480" lift at 220/220 duration and .110 separation (E303 grind with slightly smaller lift), pushing a built C4 with a shift kit and a 2400-2600 stall and 3.0 gears. (EDIT: The idea here is a daily driver setup that will scare the living hell out of the sport-compact crowd at the nearby college.)

The cam hasn't been ground yet; if there's a detriment to having hogged out the exhausts this wide, is it something I can salvage by tweaking the cam grind?