Holley spread bore story, boost referenced.


Oct 11, 2009
So, just to be different, I installed a Holley 4160 carb on the draw thru turbo. The major issue with the carb was the vacuum secondaries would not open on acceleration. In fact, it would die, !!! So after lots of questions , and no help from Holley, I sent the carb to Joe at All American Carb to be boost referenced, using the PEVR port as the reference port. What a difference it makes. I did need to use a spacer under the carb. this is an FYI only.