I understood the GM bolt pattern A833 was quite scarce, only used on the diesels or something, but might be wrong - at any rate, the thread to check is at the inliners site , and the modifications that may be required depend partly on what series truck you use it for

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics