Topic: 500f/550f exhaust on a 350f/400f - anyone try this?

[many408]

The nicest exhaust I've seen is only available for 500/550's.  Has anyone tried to fit a 500/550 exhaust on the smaller four; can it be made to fit, and if so what did you do.

[cafe750]

Anything is possible with a torch and a hammer....The exhaust port spacing between the two engine families are not compatible, without serious surgery. I have used 550 4-2 slipons on my 350F though. The pipe that slips onto the head pipe needed a bit of massaging to work, but eventually, it did...

[many408]

Anything is possible with a torch and a hammer....The exhaust port spacing between the two engine families are not compatible, without serious surgery. I have used 550 4-2 slipons on my 350F though. The pipe that slips onto the head pipe needed a bit of massaging to work, but eventually, it did...

Would someone with a 500/550 please measure the spacing; I will measure the 400 and maybe I'll know how much muscle will be needed.  I'm assuming that the forward and downward clearances will be sufficient...

[okie]

I have a set of 500/550 headers in my attic.  I bought them on eBay from someone who thought they were 350 headers.  After trying to fit them up to the 350 I discovered the error.  The bends placed them too close to the front and bottom of the engine.  350F headers go straight for about 4 inches from where they come out of the exhaust port on the engine.  500/550 start their downward(and rearward) bend almost immediately.  I suppose if you really (No, I mean REALLY.) wanted to use them, you could use a torch and bend them a couple of degrees in that first bend and make them fit.  Are you aware that those headers are double walled?  There is another pipe inside the pipe you see on the outside.  That is going to make it much harder to bend.  You will have to apply quite a bit of heat to the outside pipe in order to get the inside pipe hot enough to retain the bend.  What is this going to do to the chrome when it is heated that much? 

NOTE, the short answer you wanted is here:  Bend the first bend 2 or 3 degrees less tight than stock and they should fit without hitting the engine.

[many408]

I have a set of 500/550 headers in my attic.  I bought them on eBay from someone who thought they were 350 headers.  After trying to fit them up to the 350 I discovered the error.  The bends placed them too close to the front and bottom of the engine.  350F headers go straight for about 4 inches from where they come out of the exhaust port on the engine.  500/550 start their downward(and rearward) bend almost immediately.  I suppose if you really (No, I mean REALLY.) wanted to use them, you could use a torch and bend them a couple of degrees in that first bend and make them fit.  Are you aware that those headers are double walled?  There is another pipe inside the pipe you see on the outside.  That is going to make it much harder to bend.  You will have to apply quite a bit of heat to the outside pipe in order to get the inside pipe hot enough to retain the bend.  What is this going to do to the chrome when it is heated that much? 

NOTE, the short answer you wanted is here:  Bend the first bend 2 or 3 degrees less tight than stock and they should fit without hitting the engine.

Damm.

I was hoping it was a spacing issue, not as you describe. 

Benji's 4-2 "peashooter" is what I'm after, but he says he doesn't do 350f/400f (though the website does).