71 340 exhaust manifold bolts

Posted by: 5carguy

71 340 exhaust manifold bolts - 01/03/18 04:03 PM

Who has the best and most correct hardware for exhaust manifold install on a 71 340 Cuda?Thanks in advance
Posted by: 69bfan

Re: 71 340 exhaust manifold bolts - 01/03/18 07:11 PM

AMK Products out of Winchester, VA. Part Number C-8023.
Posted by: Dibbons

Re: 71 340 exhaust manifold bolts - 01/04/18 11:00 AM

I purchased a kit online but have a question/observation. My factory stock '65 273 vehicles and my factory stock '72 318 vehicle did not have the special round washers on the two middle-inner bolts. The rounded washers were only installed on the two outer studs and on the two other bolts closer to the studs (total of four washers on each manifold). The on-line kit I purchased included washers for all bolt locations (total of 12-for both sides).

My understanding is the washers allow for expansion and contraction of the exhaust manifolds as they cycle through heating and cooling (running and non-running conditions). It seems the expansion between the inner two bolts was not deemed sufficient enough by the factory to warrant inclusion of the round washers at those locations (although I can't see how it could hurt anything to include the washers under all bolt locations). In other words, "factory correct" installation would mean four washers on each side and no washers on the inner two bolts locations, right? (But I am not saying that factory correct is important in this case).

Anyone have any other pertinent information to my comments/observations? Thank you.
Posted by: Cab_Burge

Re: 71 340 exhaust manifold bolts - 01/04/18 12:08 PM

I'm going to say that all the stock 340 motors I took apart, A and E body, had those washers on all locations, studs or bolts shruggy
Posted by: kentj340

Re: 71 340 exhaust manifold bolts - 01/05/18 01:52 AM

I'm the original owner of a '69 Barracuda 340 that I ordered in the fall of '68. Recently I removed the manifolds for the first time and took photos. Factory was 2 thick conical washers at the front and 2 at the rear with no washers in the middle 2 places. So yes, four washers on each side and no washers on the inner two bolt locations.

These photos are left side: front, middle, middle, and rear. Right side is the same as far as conical washers.

And AMK is the best source. AMK has actual size color photos of each item they sell, so you know exactly what they offer. Items that are exact copies of Mopar fasteners are coded with the pentastar logo and show the Mopar part number. Others who sell fastener kits are mostly just re-selling AMK.
Posted by: Dibbons

Re: 71 340 exhaust manifold bolts - 01/05/18 10:19 AM

Those rusty original bolts prove my point perfectly. Thank you.
Posted by: 69bfan

Re: 71 340 exhaust manifold bolts - 01/05/18 07:44 PM

The AMK kits are retailed through some vendors and then there are similar kits that put together from a variety of parts that I feel are not of the quality of the OEM parts. So just try to determine what your purchasing to avoid any frustrations.
Posted by: dart4forte

Re: 71 340 exhaust manifold bolts - 01/05/18 11:50 PM

Those cone washers are getting hard to find
Posted by: Dave Hall

Re: 71 340 exhaust manifold bolts - 01/06/18 12:53 AM

I know it might be from the factory like that but logically it makes ZERO sense if the washers are for expansion/contraction? Wouldn't the Siamese port with only two bolts need it? Maybe a little more than the others? The studs make sense.
Posted by: Dibbons

Re: 71 340 exhaust manifold bolts - 01/06/18 08:46 AM

I think the factory exhaust manifold gaskets were metal, at least on the early vehicles. This would allow some slip/expansion just like the newer "shiny" side gaskets do. Could be the washers are not related to expansion. Where are all the Chrysler engineers/blueprinters anyway? Don't remember finding anyone with those qualifications on any Mopar Forum. Are they all sworn to secrecy or something? Weird.
Posted by: bboogieart

Re: 71 340 exhaust manifold bolts - 01/06/18 09:51 AM

I don't recall the factory using gaskets.
Doesn't mean they didn't though.
My guess, the heavy solid center section stays put, but the long thinner arms to the outside would be more prone to expansion and movement.
Posted by: kentj340

Re: 71 340 exhaust manifold bolts - 01/16/18 01:55 AM

340 exhaust manifold gaskets from the factory: driver side had the heat shield/gasket. Passenger side - no gasket.

Concerning the thick conical washers on 340, there were 4 on the driver side but only 2 on the passenger side. Photos above are the left side showing 4. Photos below are the right side showing only 2, front, middle, rear.