Good info. Regardless that 1995 3500HD was 1 wire o2 from factory. Also the weird setup where the original pancake pellet style cat was behind the muffler instead of ahead of it. And yes, absolutely was the linear EGR on that 454. I recall it, plus double-checked the pics from that truck.
Yes but with Vortec-style accessory drive.
The 10th digit of your VIN is the final word on what year model your truck is. If it's an S, your truck is a 1995. T, 1996. 1995 was the final official year for TBI engines in U.S. market GMT400's, with the very rare exception of some fleet/government type models. Always exceptions when you say stuff like that.
Richard