Small block exhaust manifolds

[Alan P Zelanski]

I was just wondering if if would be possible to use or modify the exhaust manifolds from a 318 to be used on a 360? I have a Mopar with a 318 that just blew out it's rear main seal and I was thinking of rebuilding a 360 I have to drop in the car but the exhaust system in the car was custom built for a 318 and the 360 uses different manifolds that don't match up to the exhaust system in the car. Not sure I want to have the system changed just in case at some point I want to put the original engine back in.

 

[F4R/T]

Check your port sizes and that will tell you quickly, I have a feeling you'll be choking it down.. only the dial caliper will tell! It should bolt up to the heads.

 

[JoePole]

Sure. 318 manifolds will bolt up. Flow won't be optimal but depends on what you are shooting for performance wise. You could "port" the manifolds to match the 360. What car is this in?? What size exhaust pipes? I assume you have a B body.

 

[wahya]

When I was looking for a motor for my car, I found a 340 rebuilt for sale on eBay. The guy selling it specialized in 340s and had sold a few. It turned out that he lived in my town and I went to his house to talk to him. He was in the process of building another 340 and we started talking dollars and cents. He told me that he had a nice 360 and the final price was more in line with what I had to spend, so I went for the 360. I also told him that I planned to keep my old 318 block, since it was the original motor.
I then asked if I could use my 318 heads, because then I could "store" them on the car. He said yes and he would port them and work fine. He put on an intake for a Thermoquad he rebuilt, solid lifters etc.
On edit, I put headers on, so as previous posters said.....

 

[Curiousyellow71]

I have ported 318 manifolds out for the 360 port size. Beware some 318 manifolds will hit a boss on the head and you will crack the manifold before its tight. Test fit them first...don't ask how I know

 

[Alan P Zelanski]

Sure. 318 manifolds will bolt up. Flow won't be optimal but depends on what you are shooting for performance wise. You could "port" the manifolds to match the 360. What car is this in?? What size exhaust pipes? I assume you have a B body.

The car is an 69 Charger with a 318 and four barrel with custom made 2.5 dual exhaust.

 

[JoePole]

This is just my opinion and I don't know what your skill level is but I was running 340 HiPo manifolds on a 360 (72 B body) and swapped to headers. I used header reducers, and a few pieces of pipe to adapt to my existing dual exh. I used a chop saw with metal blade and a MIG welder. Was pretty straight forward but I am sure any exh shop can easily handle this. It made a huge sound difference (for the better) and added torque.
I used swap meet headers and 01 Dakota V8 "mini" starter and had no fitment issues. I would recommend this route otherwise your 318 manifolds should bolt right up to the 360 because the heads are very similar minus the port size as F4/RT stated.

BTW....Welcome to the forum.

 

[Alan P Zelanski]

OK lets go with another quiestion and that is what manifolds from that era match with the 69 318 manifolds? In other words a have several with the same basic layout including the two on the 318 plus the two on the 360 and two others that I'm not sure what they came off of. Problem is I'm not even sure if the two in the car are original to the car as I've seen pictures of the ones someone said came off of a 69 318 from a Charger and they don't really match what I have in the car. Could different manifolds from different small blocks match from engine to exhaust system?

 

[Curiousyellow71]

OK lets go with another quiestion and that is what manifolds from that era match with the 69 318 manifolds? In other words a have several with the same basic layout including the two on the 318 plus the two on the 360 and two others that I'm not sure what they came off of. Problem is I'm not even sure if the two in the car are original to the car as I've seen pictures of the ones someone said came off of a 69 318 from a Charger and they don't really match what I have in the car. Could different manifolds from different small blocks match from engine to exhaust system?

I believe a 360 ex manifold will have a larger outlet for a bigger down pipe/large ports, but will be pretty close in shape as a 318. The 360 didn't come out till 71. Only big port sb manifolds in 69 would be a 340 and they are a lot different in appearance for A bodies. In '71 Then the passenger side manifold looks similiar to the 318 but w a bigger down pipe. Not sure what a b or e body driverside 340 manifold looks like only had A bodies 340s.