Until recently, I never knew that in the mid-late 1980’s, GM had produced another heavier stripped chassis that was maybe, perhaps; a predecessor to the P12 chassis.

This heavier stripped chassis that GM had produced in the 1980’s was called the P6T.

According to literature, the GM P6T stripped chassis was available with the (problematic) Detroit Diesel 8.2 liter ‘Fuel Miser’. The 366, 427, and 454 gasoline engines were probably available on the P6T stripped chassis.

Here are links to the 1985 and 1986 model year GMC brand Motorhome Chassis brochures up for auction on EBay that include the P6T in their lineup of available motorhome chassis at the time.

http://www.ebay.com/itm/1985-GMC-RV-Motorhome-Sales-Brochure-wc1734-YNAJCG-/370776835794?hash=item56540586d2:g:r4QAAOxydB1SnP9v&vxp=mtr

http://www.ebay.com/itm/1985-Monaco-Motorhome-RV-Chevrolet-Brochure-r1230-5ZEBPS-/290879422288?hash=item43b9c3bf50:g:XmkAAMXQ4uJSCptR&vxp=mtr

A Step Van on the GM P6T chassis for sale:

https://www.usedvending.com/i/Used-GMC-P30-Food-Truck-in-Florida-for-Sale-/FL-T-832P