I'm going to use an early aluminum intake manifold that accepts Su HS6 carbs and a late B20 chopped in half exhaust manifold. There are 2 different heights when placed against the head. The aluminum intake manifold is lower than the cast iron exhaust manifold by about 1/4". What is a good way to fill this gap? With a spacer? Otherwise you would need to aluminum weld something on that intake, which would be quite $$$.
What say you?

If you are only going to use the exhaust manifold with the aluminum carb manifold,
take it to a machine shop and have the mating ears spotfaced to the same
thickness. If you may again use it on a FI setup, go with the half washers.
(You can do it without welding them together but assembly is more difficult.)
--
George Downs, Bartlesville, Heart of the USA!

George,
I always appreciate your help with these old Volvo's.
Do you mean take the aluminun intake to be spot faced? What does that welding encounter? Will that be expen$ive?

Thanks, Duck

George,
I always appreciate your help with these old Volvo's.
Do you mean take the aluminun intake to be spot faced? What does that welding encounter? Will that be expen$ive?

Thanks, Duck

It ran about $35 for a machine shop to even them out for me. They turned it around in a couple of days.

NO!! The aluminum manifold is already thinner!
You mike the thickness of the ears on the aluminum manifold and then spotface
the ears of the cast arn exhaust manifold to match! Then you can use the
extra heavy forged washers and they work great. Don't do any welding!
--
George Downs, Bartlesville, Heart of the USA!

I guess , I'm not familiar with the word "spotface" and related it to the term spot weld.
What does the machine shop do? What kind of machine is needed?

It is usually done in a milling machine but in production operations it might
be done in a very sturdy drill press or jig borer. Normally you spotface with
an endmill to reduce the thickness to what you want in areas large enough to
accommodate the special forged manifold washers.
--
George Downs, Bartlesville, Heart of the USA!

George,
Thanks for the explaination. Now , I will know what to tell them at the machine shop.
Duck

I found some of the extra thick washers that are used where one bolt secures both the intake and exhaust. I cut one of these washers in half. I clamped one of the halfs to one of the whole washers and welded it in place. The result was a washer that was thicker on one half and of normal thickness on the other. It worked very well.