I have been looking for a new exhaust system for my 77 F150 2wd truck with a 302 and C4 Automatic tranny. Another thing I should mention is that my truck has the front frame mount gas tank, which makes adding an after market exhaust system a lot more difficult. I say this because if I use std long tube headers the DS header will dump right in front of the gas tank, so all the exhaust pipes and mufflers have to be run down the PS of the truck. The only after market exhaust system I could find that took this into consideration is sold by LMC and they're supposed to work with the stock exhaust manifolds.
So I ordered there "Performance Turbo Dual Exhaust System" (p/n-48-5552) that is supposed to fit 77-79 F-Series trucks w/ 302 engines and sells for $219.95. It came today and I was looking it over and I noticed the flange on the down pipes was not the same as the one's that were on my original exhaust down-pipes. My original flanges had a seat for an exhaust gasket (doughnut style) and the new pipes just have a open concave flange that does not look like it will work with my stock manifolds. Another issue with these down-pipes is they don't even seem to be bent correctly even if they had the correct flange for my exhaust manifolds.
I also noticed a difference on the enclosed instruction sheet about what trucks this exhaust system is supposed to fit compared to the LMC catalog. The sheet says it is supposed to fit "1977-1/2 -1991 Ford Pickup 1/2 & 3/4 TON 2wd & 4wd w/302 V8". So this leads me to the question, was there an exhaust manifold change during the 1977 model year? I am thinking my truck must be from the first part of 1977 and not 1977-1/2. Does anyone have a picture of the 302 exhaust manifolds from 1977-1/2 to 1991? Has anyone had this problem with the LMC exhaust kits? I realize that LMC is not a sponsor of FTE, but like I said earlier, I was not able to locate a bolt on exhaust kit anywhere else for my application. Anyone know of a fix for this problem? Thanks.

Jim