55 Chevy w/ 2005 5.3L Vortec LS Motor
Posted: Mon Aug 10, 2009 7:49 pm
Just finished installing a $350 junkyard 5.3L Vortec out of a 2005 GMC Sierra in my 55 chevy post. It is the cast iron version of the LS1 minux .4 liters but has identical internals. I put a Comp Cams Thumpr cam and upgraded valvesprings and pushrods. Intake is stock and I added 30 lb Ford SVO injectors and I'm using a polished stock throttle body. Pertronix headers and series 40 flowmasters with 2.5 inch exhaust and an H pipe round out the exhaust portion of the install. I did all the mods to a v3 board and I am running the newest release of the ms2extra code variant. I made my own harness from scratch and am using stock sensors and IAC stepper unit. Ignition is using the stock 24 tooth crank sensor along with the stock cam sensor through megasquirts wheel decoder. The only big problems encountered were: problems with lost sync events, remedied with enabling noise filtering; and the timing was really retarded with the ignition settings located on the ms2 ls1 setup page. I had to enter a negative 13 value in the trigger wizard to get it close. Just dynoed the car the other day and it made 298 hp and 297 ft/lb through a 700R4 automatic and 7" GM rearend with 3.55 gears. Not bad for a 289 crank hp stock motor with minor bolt on upgrades. I am still giving up some hp in the timing dept. and I think there is more to be had since we only revved the motor to 6000 rpm and it was still pulling. I will try to stay up to date.