This is a hard tail application....with a common motor/transmission bed that is mounted on rubber isolators.
Yes, I gathered that, hence my question about how to manage the final drive tension. I'm not saying it's an unsolvable problem, just wondering if you've got a solution.
The motor has over 130,000 miles on the lower end
Being a 124 you probably have some kind of an aftermarket flywheel assembly. Most of those motors are 4.125 bore x 4.625 stroke although some people do them 4.250 bore x 4.375 stroke which could be done on a stock 07-later crank. Hopefully you've got good rods because a rod failure is ugly. With that many miles though I'd be concerned about fatigue regardless.
Have you looked at the pinion runout? Is it staying straight for you? It's a big challenge at the power levels it takes to go 200.
and fresh CP turbo pistons @ 8.1.1.
Since the pushrod motor is rpm limited your only option for making more power is to increase torque and the only way to do that without making the motor bigger is to increase cylinder pressure and that eats pistons. CP makes a fine piston but when cylinder pressures get too high it doesn't really matter much who's piston you have the aluminum melts.
Turbos are popular in LSR because it helps solve this problem by letting you cool the charge after some of the compression is done but before you put it into the motor. Do you have an intercooler? That's going to be really important at this power level.
Since installing the turbo the motor has over 70 hours running time without a hiccup.
Yabbut I'd be real cautious about reading that as a good sign for LSR. You'll need to make 200+ horsepower for miles at a time. It's a whole different deal.
The motor has made 8 passes on the salt, pre-turbo, 2 with turbo set up in 2010.
How fast did it run with the turbo? How much power was it making?