Hey guys Jim isn't running a Holley here...the short runners on the webers will cause popping if you have too much cam in the engine...and getting the jetting just right with 7-8 things that you can move around is a B*#$%.....what are the specs on the cam you are running Jim?
I have noticed an increase in the amount of popping I get from my car on decel from the webers over what I had previously with a holley and single plane but I did have popping with the holley too. This is a known problem with Webers...you can have "NO" exhaust leaks or they will pop!!!!!
There are a couple of things to consider
- I had alot of popping just driving around, at cruising speed ont decelerating, with a lean mixture...I also have to get a laser pyrometer to get the mixture on all cylinders correct to make sure that isnt' some of the problem....
- I can't remember but does the undercar on your 289 connect the same way as a comp car or an ERA? Do the headers slide into the exhaust collector pipe 1 header at a time? This type of connection is a bear to seal up...I still haven't figured out how to get mine to seal yet but am open to suggestions...
My bet is there isn't a header leak but a leak at the collector where the header meets the exhaust and you are sucking cold air in on decel.....best way I found to avoid it was to take it out of gear and coast when I was going to slow down ...no downshifting unless I am flat out on the accel
Matt - Ill give $200...bid high and scare the other bidders
