Langdon recommends running an inexpensive regulator. I used a Mr. Gasket unit and I put a gauge on it to verify the 3.5 psi. However, I found it is quite accurate so I would say the gauge could be an option. I have a complete set of pics of the setup in my Webshots album.

A word of caution.....when you bolt the adaptors to the base of the carb you will find it is a tight fit. The thick insulator plate/gasket WILL line up if you just take your time and don't try to force the fit. Several folks have had a problem with this. DO NOT TRY TO ENLARGE THE HOLES.

You'll have to do some creative bending to get your linkage from the bellcrank up to the carbs. I would suggest using some heavy copper electrical box grounding wire from Home Depot (18") to use as a pattern. You'll have to mount the exhaust and intake (without gaskets or alignment rings) with a couple of the manifold bolts to get your linkage bends correct. If you're running Langdons aluminum heat plate the rear inboard corner will need to be trimmed to clear your linkage.

Your final installation will be easiest as follows: install the manifold bolts and plates (the center 4) loosely, add the gaskets and rings, then the exhaust (if fentons) I put a bolt in the front hole (in place of the stock stud)and a longer stud in the rear to keep the fentons from dropping. The intake goes in WITHOUT the carbs.....this will let you get to the manifold bolts and get them tightened correctly. Add the carbs after. If you try to put the intake in with the carbs and linkage attached you'll have a tough time getting the bolts tightened. You need to add the 2 longer bolts and plates after you get the manifolds seated. Try to get you bolts tight as they WILL loosen up after a couple hundred miles.

I made some (2)little scrap sheet metal "hats" that sit on top of the carbs to make a flat surface for the unisyn to rest on. Also have some dumdum sealer that I use to make sure they are sealed at the base where they meet the carb. I didn't have to mess with the idle mixture screws at all until after I got them synced. The trick is to get the carbs synced using the idle speed screws and then adjusting your linkage so that they both draw equally at idle. Some folks just use a rubber hose and listen to the hiss....being deaf in one ear eliminated that for me. After I got them both synced I used a tach and vacuum gauge to adjust the idle mixture screw. I didn't have to turn them more than a couple degrees to get them the way I wanted.

I used exhaust heat which was the easier of the two options...it works fine and although I'm only getting about 17-18 mpg I feel confident with a bit more tweaking I can break 20-22 mpg. If I were to keep my cruising speed down to 55 mph I know it would be there now. It's just too easy to run at 70 mph and the sound of the secondaries cutting in is addictive!!!!!

The installation is not something you're going to want to do in a hurry. I can imagine I had the intake and exhaust on and off 3 times before the final install. However, it will be well worth the effort the first time you hit the highway!!!!

Dave

Webshot "Tips and tricks" and "Shoebox" Photo Albums

EXPERIENCE is the best teacher...but it gives the test first...and the lesson afterwards.

"What this generation tolerates...the next will embrace"