Just finished the C7 to SC10-I swap into the 93 Grand Touring which is a PRS chassis
Like to say thanks to all the folks with the great posts on this board and to smallengineguy for his assistance!
This is not a really hard mod to complete and there are lots of posts on doing the mod on newer sleds
PRS use the L brackets on the front which make it a bit more interesting.
The 93 Grand Touring came with a 16" x 121" track so the tunnel is wider than some of the newer sleds
The front L brackets provide a 1/2" spacer on each side
They need to move down 1 inch and back 4 inches to give enough clearance between the drives and the front of the skid. Just take the L brackets mark a 1" line and straighten them out in a vice and then rebend the bracket 1" shorter to drop the skid. On this sled the brackets end up on the rear side of 3 rivets on the tunnel.
I used a piece of flat bar and marked it for the SC10 CTC of 24 3/4" and drilled it so I could mount in the front L brackets and to get the rear brackets in the right location
Mounted the Front L brackets onto the sled without the skid first but with the flat bar bolted on
This gave me the CTC mounting distance on the rear
As my sled has the wider tunnel I need to use 1/2" spacer on the back to mount the new skid
I had a spare set of front L Brackets so I straightened them in the vice and with about a 1/2" bend on the top end they fit perfect for the rear mount as to the height from the tunnel top
Put the L brackets on the front of the new skid You will have to narrow up the plugs in the sc10 skid about 1/8" to make the side to side fit properly. Measure the side to side of the old skid and make sure the new one is the same!
Couple of bolts and some steel poprivets and the job is done
I used the cross shaft in the middle of the tunnel from the SC10 I skid and mounted it in the same holes the shocks on the C7 used to ensure the track does not flop around in the middle
Hardest part of this mod is getting the new skid to push back into the tunnel far enough for the new mount holes
Use a rachet strap and pull down the front shock to give you extra room and drop the rear shock and springs down Makes the job a whole bunch easier.Keep the sled rear in the air and use a floor jack to raise the front of the skid to match up the holes worked the best for me
This took me a couple of nights to complete but I think it is well worth the effort
Here are some pic's