How important is the rings that seal the intake manifold to the head? I have a late 235 and am using a early 235 intake/exhaust and the rings would not fit in the block so I left them out. Now the engine does do run unless 80% choke is used and backfires thru the carb once the choke is pushed in. ????leaking intake manifold??? Do I need a late 235 intake and rings for a correct fit???
I think if you use 216 gaskets you could get away without using the rings. On jobs where I use the 216/early 235 manifold on a late 235 I make bushings to fit in the head to reduce the size so I can use the smaller alignment rings.
You're using a 216 intake manifold and it'll always leak unless you make up some stepped rings , it is far easier to just get a good used 235 intake manifold , remember the truck intake manifold has a horn mount boss on it drilled & tapped , some car intakes have the boss but it's not drilled and tapped .
How you tighten it up is important too , begin tightening in the center and work outwards .
I've bored the (3) intake ports on lots of 216 intakes from 1.437 to 1.531 to allow the use of the 235 rings. Then everything fits right together.
Barry,what do you use to bore out the ports?What works the best?
I do them on a Bridgeport (milling machine). It should be a pretty simple (inexpensive) deal to have done if you have a good, small, local machine shop or know a buddy with a mill in his basement or garage. Many engine rebuilding type machine shops may not be equipped to do this however, as they usually just have the equipment to bore blocks and do head work.