I had a 1999 vortech 350 shortblock installed in my 1994 Suburban and used the old Throttlebody with adapter, exhaust, etc. The new engine works best at 30-38 degrees advanced base timing but still has a hesitation about 2000 RPM when in closed loop. We tried Howell Engineering chip for the prom and several different proms, computers, etc. Does anyone know a chip or prom or fix for this Vortech swap. We don't want to go to the expense of a stand-alone computer. Thanks