crossbreed383

iTrader: (1)

Hey all
i have a 14-5comp 408 i just started for the 1st time last saturday
this thing seems to crank slow even though it has a new fully battery(900cca)
and same 00 battery cable that was in the car with my last race engine(old school 383sbc)
all i changed was going to a ls engine along with going from a aftermartket tci sbc starter to trying the oem ls starter
im wondering if the stock starter might be the issue
its out of a 06 yukon w a 5.3 i think?
im wondering if an aftermarket starter is better than the factory starter in terms of cranking rpm
if so is anyone using any specific piece, and if so, do you have any cranking rpm data
thanks