Stock '77 620

[Dr. Scagpoople]

Hello all,

 

Just got my first 620. It has all the original smog gear in what seems to be great shape. Original carb is missing the big spring in the accelerator pump assembly, but it works other than that. I am changing to a weber 32/36 and junking the smog equipment, my state does not require on '80 and earlier. Does anyone need the smog equipment? Does anyone have an intake or exhaust that have worked well with the L20B. From what I understand the L20B is the better engine, right?

[DatDoug]

You can use your original intake & exhaust. They will work fine. You have to block off the smog stuff. If you want a cleaner look you can get an early L16 intake mani & hog it out to fit your intake ports. You also would want the exhaust mani from the early L16. It will bolt rite up to your head & downpipe.

 

POST PICS OF YOUR TRUCK :P

[datzenmike]

To disable the EGR just pull the vacuum hose off the carb. Plug the carb end. Cost nothing and works instantly. Look for the separate intake and exhaust when they come up cheap. Air pump and hoses, anti backfire valve can be scrapped. Metal air injection lines can be crimped shut or removed entirely and pipe plugs used to seal the exhaust manifold.

 

Things to keep in mind if using the older 'non smog' manifolds:

You will also need to change the exhaust down pipe to the muffler with the older manifolds.

Your intake is warmed with hot exhaust. The older intake is warmed with coolant water from the head. Your U-67 won't have the holes so they will need to be drilled out and a hose run from under the front of the carb down to the lower rad hose inlet for this system to work.

[Dr. Scagpoople]

Thanks for the infor guys!

 

I found a few used weber's here in the area, I think I will try getting a used one to save some money. I will be pulling the smog equipment this weekend for sure. A question for Datzen Mike, The additional coolant lines are just for the older intake conversion, correct? I plan on just plugging all the extra holes in the stock intake and exhaust manifolds with copper plugs. My truck as the 3 speed auto, is any one familiar with this transmission?