[lxfiveoh]

Boring the stock MAF was an option back when the only aftermarket meter was the $500+ Pro-M 77mm air meter. Porting quickly went out of vogue when cheaper $179-$200 Pro-M's and C&L's became avaiable.

I *did* see an article long ago where a bored out MAF beat out a Pro-M & C&L in a drag test, though. What boring out the stock MAF will do is lean out your mixture, as the MAF is now flowing MORE air than the EEC KNOWS. The EEC thinks it's a 55mm channel, when it is now a 60 or 61mm channel flowing air.

I wouldn't bother.

FWIW, I went FROM a 75mm Bullet MAF to a stock MAF on my car (GT40 alum heads/Cobra intake/65m TB/full exhaust) and lost only 4rwhp on the dyno. Not a big difference...