340/mag360 exhaust manifolds

mopar56 said
I noticed in some of your pictures you have some center dump manifolds but you dont mention them much, I am on this site because my youngest son has a Duster but MY project is a 56 Dodge truck on a 83 Dodge truck frame, its still going together and I am just trying to figure out my exhaust now, what I need is center dump on both sides, what I have got now is d/s from a "A" body 69/70 318 and p/s from a 80 Dodge truck 318 but they are the smaller exit, also I tried the later, (80,s) 318 center dump on the d/s of the truck but it is two thick at the end and touches the fire wall, ( remember this is a street rod), sooo.. my question, is the center dump you have a large diameter exit and tight, ( short bolt ) at the ends? , thanks

Well in order to give you a clear answer I need to know if by "large diameter exit" you mean 1 7/8" or 2 1/4". Mopar cast iron manifolds came in a center dump style (70s 340 with 1 7/8" exit hole). The 360 magnum and Dakota are 2 1/4" exit hole but they are all rear dump. I just posted an example (see below) of a 340 close to center dump, but they do make some that are closer to a center dump, they are 1 7/8" exit hole (70s 340 manifold). I had a friend here in town that installed a large hole Dakota and a 360 magnum large hole manifold set on his 40 dodge truck (318 engine) and there was plenty of room. I also have an 80s 318/360 center dump manifold (third pic) with a exit hole that is a little larger than 1 7/8". As you probably already know...the standard 318 Low perf manifold is 1 5/8" exit hole.
Please let me know what you mean by "large diameter exit" and I'll help you as much as I can whether you but anything from me or not.

Thanks,
Treblig