New Dual Exhaust on the Y block...Need Help Designing Front Block Off Plate

I got a new exhaust done on the 54 with the 239 y block. True dual exhuast with 2" pipe and 12" gl***packs. Front cross-over pipe was done away with. Drivers side comes forward off the exhaust manifold and down under the car. P***enger side was capped off. Sounds great! Loud when I want it to (but not obnoxious) with lots of rapping and popping. Most importantly, no more exhaust g***es leaking into the cabin.

Muffler guy did a great job. 2 hours of work and only $300 (Cl***ic Muffler in San Jose). The only problem I have with the job is the ****py way he capped the p***enger side. I want to design and fabricate a new finned block off plate for the p***enger side exhaust manifold. Problem is that I dont have the car in front of me right now and I want to get it done today.

Can someone please give me some measurements of either the cross-over pipe flange or the gasket?

I need the mounting stud spacing and stud diameter. It would also be nice to get the measurement across the flange in both directions.

Thanks

 

Wouldn't it have been cheaper and easier to get some later exhaust manifolds that exit the rear and don't have the crossover?

 

i didnt even need to buy another manifold. i could have flipped the manifold around so that it will dump out the back becuase the mounting locations are the same. problem with that is the steering box and linkage is in the way. no way to fit the pipe out the back.

i did find out that the 256 y-block in police interceptor models ran dual exhaust with the same configuration as I have. Apparently, they came with a block off plate on the p***enger side from the factory.

is this true?

if so does anyone have one so that they could give me some specs?

 

Did your muffler shop have a.......gasket in stock he used for the blockoff cap?

Pattern.

 

I might have a pair of dual exhaust manifolds from a 55 but its too late now.

 

He actually didn't really make a block off plate. He just crimped and welded the pipe a couple of inches from the flange. Looked really stupid. Too late anyway. I went home on lunch break and took off the flange. Took it back to work, designed a finned block off plate and milled it out of aluminum. Looks really nice and works extremely well. I will post some pics later and maybe add a video of the new exhaust.

 

That is a rinky dink way of doing things. No matter what kind of block off plate you get it will be ****y. I suppose you could get a cap off of laker pipes. I did duals on mine but I got the manifolds and did them right. I remember "back in the day" when people would do that, in fact I saw a picture like that somewhere on the HAMB awhile back.

 

I'm just trying to do the best with what I have.
It did turn out nice though.

 

i just got me a 56 customline and was thinking about making/buying a dual exh. set up. i'm interested in what yours looks like. can't wait for the pics!

 

I had a 54 vicky and ran 312 manifolds. went to the local hotrod shop pickup 1 3/4 u bends and fabbed up a starter pipe around the clutch arm. The dual exhaust really woke the car up and worked alot better for the tripower.

 

All you have to do is get a 55 or 56 clutch arm, they have a bend in them. Bolt on.