Exhaust Crossover Block-off Plates

[quick86silver]

Has anyone used these before? They are plates with recessed areas and not plugs.

[BigDan]

are you talking about the original plate that use to block one exit on the SBO exhaust manifold when dual exhaust ?
Dan

[quick86silver]

No, the exhaust crossovers on the intake manifold to head ports.

[BigDan]

in any performance application you have to block these passages ....

if used in normal driving in cold winter weather do not block these passages .oherwise your intake will stay cold and cause problems
Dan

[88hurstolds]

I ordered the plugs from Mondello and spoke to some dude with an attitude on the phone. Dickwad sent me these plates you speak of instead of the actual plugs. The plates look like a disaster waiting to happen, definately fear that there will be two extra tailpipes coming out the top of the manifold if I use them...

[retiredmech2]

I can speak only for 455's. from experience. There are plugs that have to be grind and filed to put in the heads where it matches the cross over in the Aluminum intake manifold you don't need to do it if you are using a cast iron manifold. There is also a new thing on the market where you melt it and pour into your head. I've found out by experience if you don't block out that cross over you will crack the underside of an edelbrock manifold if you do a lot of hard driving. I have two of them in my garage at the moment.

[88hurstolds]

Well I am using the plates on my 455 and so far so good...

[retiredmech2]

Oh, you chatted with the Idiots at mondello.They charge way too much and will send the wrong part and hassle you when you call. Joe himself has nothing to do with the store in Calif. 15 years ago He was available to chat and answered tech questions, he was always helpful. He had a very good reputation. He turned the business over to family and it went streight to hell. The plate is good for non performance. If you are going to break in a cam the start up and 20-25 min at 2000 rpm it gets real hot. It gets hot enough to burn a new set of ceramic headers.