91Firecrow305TBI

Here's my situation. I'm looking for my next mod, and I've got it nailed down to two choices.

I've already got all of the free mods, including the ported stock maf ends, a lid/filter, SLP bellow, BMR LCA's & relocation brackets, a Pro 5.0 Shifter and a Motive 4.10 gear.
I ran a 13.033@109.34 Friday Nov 1st with a 2.045 60' and a 8.5@85.6mph 1/8th.

I've got a race lined up against a 300z TT from a slow roll or dead stop all the way to 120mph. I'm looking to make my car a little faster in preparation.

I do most of my racing not at the track and have significantly less traction, not at the track. I spin most of the way through second and chirp 3rd hard. I have a Hard-top, non T-top car due to my experiences with a 91' Firebird T-top car.

I've got money to either:

A. Buy and weld on some boxed BMR SFC's... How much more traction will this give me considering I already have the other BMR stuff?

B. Replace my stock ported 75mm MAF with an 85mm Maf and buy another throttle body and have it sent off to be ported to 80mm... What is the size of the stock TB? How much power should this give me over the ported MAF and a non-bump-stop modded stock TB? Thanks