Any one know of a source of Tri Y Headers for a 351C? They're for my 56 Panel. I want as much low end tourqe as I can get. Panel will be used for daily driving and towing. It's currently got a C4 but am looking at a AOD to get better gas mileage. Has 3.70 9" rear gears with 28" tires.

 

I suspect you're going to have to get some built. Or buy a header kit, bust out the welder and chop saw!

 

I found shorty headers from sanderson headers : http://www.sandersonheaders.com/1953...1C-400M-Power/

 

Doug Thorley is usually your try y header company, if not try hedman, if not modify a used set of headers. Most of the hard work is all ready done that way.

 

Not sure how to mod a set for Tri Y performance. Any suggestions?

 

35 years or so ago I put together a set of try ys on a 75 dart that had the 340 out of a 69 gtx. this was done over 2 evenings at a wrecking yard in middle of nowhere small town Manitoba. The owners son gave me this formula. For trucks and big blocks you multiply your bore x stroke and that number becomes the length of your tubes. On a 351m or cleveland that means your pipe length is 14". In english that means the pipes coming off your motor get joined at the 14" point and the next 2 pipes get joined 14" later and the end of those 2 pipes is where you put your collector. Hence 2 into 1 followed by 2 into 1. For torque your headers should be a total of 32 - 36 " total including collector. Try to match your pipes to opposing cylinders according to you firing order on each bank. your x or h pipe will balance out your motor bank to bank.
My first pipe was 1 5/8" and I stepped it up to 1 7/8" at the joining point. I was lazy and ran the pipes outside the frame rails. The fenders and inner wheel wells were off at the time and this made life a lot easier. Fender wells are easier to cut than pipes are to shape, especially in tight spots.
For high reving small blocks you shorten the first set of pipes to half the number you got when you multiplied your bore and stroke. The first set of pipes control how fast your motor can exhale and the second set of pipes control the mid to high end of your power band. Shorter for horse power, longer for torque.
THIS is not a died in the wool computer designed program for headers. It's the mennonite farm boy program tested at Gimli dragways ( the same place the jet glider landed at) google gimli glider and dead straight highways. 15 to 30 mile straightaways.
The advantage of used headers is that the welds and bends on your mounting flange are allready done for you and all you have left to do are adjustment bends and lengthening or shorting pipes. the headers I started with were a tossed out set.
It's been 35+ years since I did it but I intend to build headers for my 78 if I can't find a set of decent headers for my truck. Ie cheap.

 

Great info! I'll give it a try since I'm having no luck finding them.

 

Fascinating story!!

 

Stan's headers will build you a set of tri-y I already asked him if he would for my 77 400

 

What does Stan's charge?