OK, so I took the plunge and put in a GMPP crate 383E stroker motor a
few months back. Was a pretty easy swap. Instaled short tube
headers and a new High torque starter. Transfered over everything
else, including the entire Vortec FI system (as GM recommend.
Set everything as close as I could get it. It fired right up and
seems to run OK, but.... after 3000 miles and 3 oil changes, the
thing just doesn't seem to have a whole lot of pep, and the gas
mileage is horrible. the old 350 that had 275k on the clock
delivered a mix of city/hy of 14.5 (on regular). This pig can barely
get 10 on premium, and when I hook up my 24; car enclosed hauler, I'm
way down into single digits (6-7). This is unacceptable.
My thoughts are I might have a clogged cat or possibly leaking fuel
injectors in the spider, but have no way to test them. No codes are
popping up, and other than a very slight exhaust leak on one header,
no ticks or bad noises.
I'm stumped and could use your help.