Heya JONNYFJ, would that 38/38 you put on your truck be a progressive carb. I guess I'm asking if both barrels open at the same time or does one open to a given point upon throttle movement before the second barrel opens. If both actuate at the same time, this could be your problem, Not enough motor for the carb.
I'v run many two stage webbers and never had an issue.
Hey J, I just looked at their site and noticed they offer the 32/36 Webber kit for a few more bucks. This is same unit I've used on every four banger I've owned, save for one I'm driving now. when my stock ASIN goes bad I'm going with this one. Smaller primary and ample secondary. Word!