L31MaxExpress
I'm Awesome
Anything after 1970 is going to be low compression and questionable head flow. A stock 74 454 truck engine was rated for 240hp/355ft-lbs. A 99 Vortec 350 was rated at 255hp/330 ft-lbs. A 99 Vortec 454 was rated at 290hp/410 ft-lbs.
Holdener has a few videos with the GEN VI 454, and with just a cam, you can get to 400hp/500ft-lbs pretty quick. The Gen VII 8.1L is still a beast though. Beats out the 454 in everything. Low end torque and high end horsepower is better across the board. The only downside is that there is basically no aftermarket for it unless you want to spend big bucks with Raylar.
A small aftermarket has not stopped LT from turboing his and running impressive times.