i have a 99 rcsb that i have been grudge racing for a few years and the 5.3 has had all she is going to take. i have noticed severe power loss, and compression is getting low... i have a preped big block that i have always wanted to put into a truck, just not this one, but i think that it is time. the new motor will be 535ci and should be somewhere around 800 hp on the spray. i just wondered if any one has any tips that i might need to complete this swap. the tranny will be a th400 w/brake. thanks for looking and i have enjoyed reading all the swap projects that everyone else has going. i just want to say i really liked my ls base motor, but i have always been a big block fan. the ls motors are strong, i should know i have been spraying my 5.3 with a whole lot of laughing gas over the years, and the only upgrades i ever did were rod bolts, cam, v/springs, fuel pump, and injectors... good luck everyone.
big T