Mysterian rear shock length

[csatte02]

Looking to order a rear shock for a Mysterian. I'm looking at the penske 8300, but want to confirm the length. Anyone have that info. The one that came off the car was old and probably not the right length anyway so I dont want to go with that one. It's an m2. Thanks Chris.

[Hawke]

I sell a lot of shocks for old race cars. This method works pretty well. Never use the length of the existing shock as being correct, even if it is the original. Most shocks are made in 1” increments. If you have to compromise, make rear longer, front shorter. Some manufacturers will have longer top eyes in 1/4” increments.

Put the car at the correct ride height. Measure the lengths. Call it B. Raise the chassis 2”. Measure again. Call it A. Put chassis on ground. Call it C.

A-C = stroke. C to B should be 2/3 of A to C. Bump should be 2/3 of stroke, rebound 1/3.

You must have adequate rebound on the rear. At ride height, tilt the chassis 3 degrees. If you haven’t overextended the shock, it’s a good start.

As it's a Vee, you probably want about 50 lbs resistance at 2 ips in both bump and rebound.