6.2 with a Banks kit surging

[Lightyear]

I've got an '88 Suburban, 6.2 with a Banks Sidewinder. Had the trans rebuilt in Feb, and about a month ago, it developed an odd behavior. It will 'surge' at times, almost like a lean stumble in a gasser. Just replaced the fuel trnasfer pump; no noticeable effect. It starts, idles, and runs fine. Commuting here in a
ATL gives me 17-18mpg at 65mph. Any ideas?

[catmandoo]

my 92 has a surge too, i have a feeling my pumps takin a s#*t it's been getting worse very slowly over about the last 20,000 miles mine will even do it after idling for a couple of minutes and go to take off let out the clutch get up to about 10 miles an hour and wham if it was a drag car the frontend would be off the ground it throws you back in the seat that hard.then it's fine ,but latly it's been feeling like it's missing on occasion,

[britannic]

Check operation of the CDR* valve (use search to find gmctd's excellent threads on how to do it in the 6.5 and 6.2 forums).

Check for air leaks in the fuel supply (pressurize the fuel tank with 7-10psi if necessary).

Check your timing and timing chain play (this is much less likely to cause surging).

CDR=Crankcase Depression Regulator valve