rc356s if you use the correct Guide S-6 that is 18 inches it will not extend in the cab too far. Here is a picture . The drill walked a little on on the inside however not bad Guide is still in business and has parts and tech support. PM me if I can help.
Mtneermike

1953 Chevy 3100
261 and SM420
53Chevy 3100
1953 Mack Firetruck
1972 Porsche 911
1986 Honda Goldwing