[RICK LAKE]

FAST427 First name would be nice. Solid mounts have good and BAD issues in cars. Here's what I have done to my ERA car rearend. I went to solid poly bushing for lower control arms. I slotted them for greasing of them. They are 14 years old and still tight. The rubber cage mounts are still tight and working good. Kept them clean and dry with light coat of grease to protect from weather. My motor mounts are the oem ford units with bolts going through them to act as a solid mount with just a little give. Trying to limit the vibration in the car between drive train and frame and body of car.
427 here's the thing, if you want to drag race your car, an IRS is not a good unit for this. I am not saying it isn't done. A solid 9" ford would be the way to go with a 3 or 4 link setup. I built my Jag setup for 600/600 hp and torque. Chrome moly shafts, locker for dana 44, carrier cover to support carrier caps, and watch the tires and rpm from a stop.
5,000 rpm launches are great if you have the correct drivetrain. When I do drag race the car, I leave at 1,400 rpms and roll onto the throttle. This stops rearend walking and schutter in drive train. I run a twin disc and it locks up quick. These car where never ment for drag racing with IRS rearends. I can see SB cars with good HP and not alot of torque. BB motors with 400+ ft of torque is a different problem.
Last note I run a soft setup for the rearend of my car with springs and shocks. I get about 1-1.5" of squat and leave, no tire slipping. Ran about a 1.8 second 60' time. Tire pressure in the high teens and a little higher on l/s rear because of the fat driver. Car goes straight. Wheel alignment and thrust angle are also very important for straight runs too. Good luck. Rick L. Ps would still like to see a couple of pictures of the rearend mounting system. Any chance of going to a larger bolt setup? 16mm or American size?