Given the OP's comment below:
...it has a Complete tune up recently done, timing verified with a timing light, new fuel filter and pump...
...I honestly can not even imagine such a tune-up not covering something as basic as Carb 101: is the accel pump working? is it providing good enough volume of fuel? etc, etc.
But anyways...so my feedback is based on personal experience with different LB computers, specifically the timing differences programmed in on a 2 bbl vs 4 bbl setup.
In my case (many many years ago, so memory is a little faint) I picked up a 4 bbl setup at a swap meet. Given that I just installed my first 4 bbl carb (Carter TQ) I thought this would have been a great improvement. Well, something was probably wrong with that LB module because that very night I took the car out I had a massive backfire after a WOT run which literally blew off the muffler...LOL, yeah, impressed all my buddies, but gave me a busted exhaust pipe.
Sooo...off I went digging into the specs and all that, eventually found out that the 4 bbl unit did have a different timing amount (initial, off-throttle and vac-advance) that would have been the right move for my setup had it worked correctly. Who's to tell if I simply missed an additional input of some sorts though...I studied that darn hook-ups, but was just cutting my "teeth" on LB era Mopars at the same time.
Anyways, like I said, for what it's worth given my hands-on experience.
