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

 

I had mine custom made.

2 3/4" True duals with H-pipe

Cost $200.00 Cdn in 1994

 

Did you use headers or your stock exhaust manifolds? Did you have the front gas tank on your truck?

 

Has anyone with a similar style truck found a good after market exhaust system that they would recommend? I really don't want to go to an exhaust shop, because I am putting this exhaust on a frame-off restoration project and all I have assembled on the frame so far is the suspension, steering, engine, and transmission. I would like to get the exhaust system installed so I can do the cam break in and have a vehicle I can move under it's own power again. The front gas tank really makes the exhaust upgrade more difficult and limits the choices I have. I was wondering since my stock manifolds don't seem to be right for this LMC exhaust kit, that I may be able to make it work with a set of BBK shorty headers. Any ideas from the exhaust experts out there? Thanks.

Jim

 

Maybe you could lose the gas tank and install an aftermarket one in the rear under the bed. With the bed and cab off, now would be the perfect time. Is this feasable?

Another old ignorant guy.

 

Getting it custom made is going to be your best bet

 

Yes getting rid of the front gas tank was something I have been seriouly considering, but this change will cost me. Not just the tank, but I would need a new sending unit, fill / vent hoses, and fill tube. Even picking out the right tank can be confusing, since I don't have an old one to compare with.

 

This is not JMO, but that of experts: DO NOT use shorty headers.
www.headerdesign.com
How are your fab skills? www.burnsstainless.com
Go to the Tech section at Burns Stainless. I know, a lot of this info is racing related, but it applies to the street also.
If you're serious about getting the most out of your engine, try www.maxracesoftware.com. Check out his Pipemax software examples. He starts at the header and collector sizes and lengths, x-pipe and muffler locations, and ideal overall system lengths. Believe it or not, the placement and lengths make a world of difference.
Of course, this might be beyond your budget, but I build several engines a year, and his software (Flowmax and Pipemax) have really been a good investment.


Pete

 

I don't mind making some modifications, but I'm really not into designing my own performance exhaust system. I have a mildly modified 302 engine in my 77 F150 and I am not trying to travel the miracle mile. I just want it to sound good and not be too restrictive. What headers would you recommend? My 302 has an RV Style cam, Weiand dual plane manifold, and a Holley 600cfm 4160 4bbl carb.

A1 Auto has some 1980 302 manifolds that I think may allow me to use the LMC exhaust kit I purchased. Anyone see any reason that these 1980 manifolds would not work on my 77 F150? Thanks.

 

I have the original manifolds and the Aux mid-ship tank.

If it was warmer and no snow on the ground I could take a pic.

 

You don't have to use stainless tube to build your own. There are many companies that sell assorted Mandrel bends. By some same size exhaust tubing locally, cut to fit and tack everything together, weld it complete when your have all the pipe fit where you want it.... I've done it on a lot of projects, some stainless some not. My only issue with the exhaust shop systems is that 99% of the shops use the cheap bender and not the mandrel bender so all your bends have the dimples... As for a store bought, bolt on Mandrel bent system, tried a couple, still had to cut and fit to get everything where I wanted it. Mine is a labor intensive method of installing exhaust, but it depends on what level of fit and finish you are trying to attain on your truck....

 

can you put the originals and the 80 units side by side the biggest thing is clearance issues and gasket pattrerns

 

I had removed the midship tank on my f150 400/c6 for dual exhaust. I used some flowmaster headers from autozone about 9 years ago ($99 pair), had a local shop bend me some new pipes to dump right before rear wheel. I got some generic "turbo's". total price:

Headers $99 + tax
Mufflers (2) $40
exhaust labor and piping custom bent $135

About $280 total I think. You will definitely want the collectors welded on whatever headers you use. I had more trouble with the collectors than I cared to have, so I went back and had them welded. I am considering some new mufflers and tubbing from headers to the back. I want something stainless that wont rust which is now happening.

The best part of the whole job was sneaking to the muffler shop driving with OPEN HEADERS The sound was amazing!! I caused quite a ruckus all the way across town.

 

I don't have the 1980 manifolds to compare them to my 1977 ones, that is why I am asking to see if anyone has done this before. I know they will bolt up OK, since I have late 80's E7TE Heads on my 77 302 now. I think this might be the best way to get the aftermarket exhaust I purchased to work, but I would really like to know if this is the right thing to do before I purchase these knew manifolds.

 

JC whitney has the stuff you need. They have the larger capacity (40 gallon I think) rear tanks. You have all the needed bolt holes and clearances on that frame. It would be a good exchange.

**EDIT** Sorry I just re-read and saw you have already bought some exhaust. There must have been an issue during 1977 because I had to send some headers back that were supposed to fit. I ran into a transmission clearance problem (had to get a B&M Floor shifter ) also had clearance issue with the transmission frame piece that goes across the frame. They re-ordered some and they fit fine.