It's an 8V71, not 61. V8 8 cylinders, each displacing 71 cubic inches. 2 stroke diesel, intake valves, exhaust ports. Very inefficient engine for varied rpm useage Great in off road applications like cranes and generators and such where they can be run at rated RPM all day long.
First truck I ever owned was a 1962 Kenworth cab over with a 318 double breasted Yamaha and a 4 x 4 twin stick. Was the only truck I ever owned that you had to downshift to go over a cigarette butt. Never change the oil either. Just keep adding as it puked the oil out on the pavement from the road draft tubes constantly, a signature of a 2 stroke diesel motor.... and they are still in production today as vocational engines.
None of that has anything to with my OP about air dams or airfois on truck campers.
Just want to set the record straight, you were off by 10 cubic inches x 8.
