shiftpro
Full Access Member
- Joined
- Aug 31, 2012
- Posts
- 4,855
- Reaction score
- 6,092
- Location
- BC Canada
- First Name
- shiftpro
- Truck Year
- 73-87
- Truck Model
- 1500, 2500, 3500
- Engine Size
- 350, 383, 454, 496!
FWIW, I got a set of Flowtech longtubes on my 86 K20 with 350, th400, NP208. I had to modify the AC bracket. The instructions explain how to do that. I also had to switch to a short oil filter. The driver side header was hitting my filter. With the short oil filter I have 3/4 inch clearance between the header and the filter. On the passenger side, the reducer flange is VERY close to the front driveshaft. I did have to move my starter wires a bit, and I plan to put a heat shield between the starter and exhaust tubes.
I have hammer clearanced both BB and SM headers around the starter. It certainly didn't touch, but I figure another 1/4 of air will never hurt. I also am known for wrapping the side of the starter (nearest to the headers) with cheap but effective heat reflect tape. It's a woven tape with metallic reflective surface. This material can be sourced through dirt bike parts... and I'm sure other places but that's where I got it. I used to put a few layers on the bottom inside rad tank. On the shifter side. It actually helped and so I have confidence it keeps even a Chev starter a little less scalding.
If you have oxy/acet torches handy, don't be afraid to use some heat on those tubes you want to adjust. You can do it cold but...