Originally Posted by
Fast4.7
That must be a superceeded number. I know for a 100% fact that a 99 and possibly 2000 LM7 has a smaller cam than a 2002 LM7. Never have cared for a 4.8L or 5.3L so I have never really looked into what garbage GM put into them from the factory. Only paid attention to the 5.7L or larger. In the past 10 years I have bought 5 different iron head, long crank 6.0Ls that nobody wanted for less than $500 each and all 5 had under 150K on them. I bought a 2006 Gen 3.5 6.0L with 80K miles for $450 with a damaged timing cover and sheered off compressor mounting bosses as well. So why touch a smaller engine. Buy the iron head 6.0L, yank the heads, put $50ea junkyard 862s on it, a cam, bolt it to a 4L80E or TH400 and run the snot out of it.The early GenIIIs are absolute DOGS! They would not outrun the older 350s until GM started putting electric fans on them. 99s also had tiny injectors like 19 or 21 lb/hr from memory. Add the two variables together and you get the differences you see.