318 stock exhaust

[74 DART SWINGER]

I was woundering if I should get some 360( since they have bigger ports) manifolds and port or clean them up alittle and install them on my 318, beacuase Ill have to wait like 1 year to install headers. Should I get some and install them? and would it increase power slightly? thanks

[Ausydad]

Why the wait?? Most places that I have seen will charge about $60 per on exhaust manifolds that aren't cracked ( if you can find them). The cost of a set of Hedman's are about $99. I'm not necessarily recommending Hedman's (personally, I hate them), Just trying to show the manifold vs. headers cost is about the same. If there are other reasons, like emissions laws waiting for exemption; then the 360 manifolds would help increase flow but won't help performance enough to really justify expense if you still have to run the single pipe......

[dwc43]

Originally posted by 74 DART SWINGER
I was woundering if I should get some 360( since they have bigger ports) manifolds and port or clean them up alittle and install them on my 318, beacuase Ill have to wait like 1 year to install headers. Should I get some and install them? and would it increase power slightly? thanks

The 360 manifolds will help you a little, but hte magnum and r/t manifolds are better flowing in stock trim than the older stock 360. 2 1/4 pipes with an X pipe installed will really help you out with the manifolds, but you will get even more hp and tq increases with it once you install some 1 5/8 street headers. Hedman and Hooker make some fine pieces for your car around 100 to 125 depending on where you get them. Some high flow flowmaster mufflers will help you out too. Check out www.drgas.com and look at there merge X pipe connectors and there gains with them. You'll really wont a set by the time you get it done. Hard to loose out on the hp and tq gains from such a simple mod.

[Dart 65]

There's a big difference between 318 and 360 ports. Bolting on a regular set of 360 heads won't do you much good without some major porting, and by that time, it wouldn't be worth it. Get a 360 to start from, and go from there. The 318 is a decent engine, but it's not really performance material. By the time you spend the cash to get a 318 seriously moving, you could have built a monster of a 360.

[FASTDARTCHESTER]

hey dart...

what are they going on? i have a set of smallblock headers you can have if you wanna pay the shipping.

i got them from a friend...one has been 'reformed' with a hammer; it still looks ok though. they were on a b-body but he told me they those 'universal' blackjack headers that also fit a-bodies (not sure if that is possible).

anyway, you can have them. i will let you know what freight is, if you'd like.


td

[dwc43]

Originally posted by Dart 65
There's a big difference between 318 and 360 ports. Bolting on a regular set of 360 heads won't do you much good without some major porting, and by that time, it wouldn't be worth it. Get a 360 to start from, and go from there. The 318 is a decent engine, but it's not really performance material. By the time you spend the cash to get a 318 seriously moving, you could have built a monster of a 360.

The only thing that I would port is the pockets. The 360 heads flow much better than the 318 heads to start with since you can out on 2.02 valves. They dont need major porting, The 318 is a real good performing engine. It's very torquey down low and can be made to run with just simple 360 heads and intake with good headers and exhaust. There's too many of them out there in IMCA modifies out running chebby's every SAt. night to prove it. We've built several ourselfs and turned them as much as 6800 and wore out some chebbys in super street dirt track cars too and they are much heavier than any IMCA car. So the 318 is a real preformer, that is if you know what your doing.

[Dart 65]

The 318 is fine if you need to stay within certain CID limits for racing, but I am referring more to street performance. Unless you are need to use a 318 specifically, there's really no point to building one up.

[dwc43]

Well a mopar mag just took a recon stock 318 long block, put an edel intake and demon 650 and headers with a 268 276 cam and it made 292 hp with 340 ft lbs of torque so I dont think that's anything to sneeze at. With X or J or U heads with 2.02 valves a better cam, intake ,and thermoquad it would have made much more. Sounds like the ymake a good street engine when you have one just laying around. 300 hp is easy to achieve with this engine if you know what your doing.

[Dart 65]

Why are you always trying to pick a fight? I didn't say the 318 was nothing more than a boat anchor, did I? I simply said that it is better to start out with a 360 since it already has 42 cubes on it. I know you can make power with an LA 318, but it makes more sense to sink that same amount of money into a larger engine to begin with. That's a fact and I will always stand by it.

[skydome]

If you have a good 318 in your car, the top end from a 360 will certainly help breathing. The factory did it. You just have to be careful with head selection, because you can change the CR. This swap, with a bit of cam makes a 318 that sounds good and gives a good balance between power and economy.

[dwc43]

Originally posted by Dart 65
Why are you always trying to pick a fight? I didn't say the 318 was nothing more than a boat anchor, did I? I simply said that it is better to start out with a 360 since it already has 42 cubes on it. I know you can make power with an LA 318, but it makes more sense to sink that same amount of money into a larger engine to begin with. That's a fact and I will always stand by it.

Not picking a fight. I just read the info and thought I'd pass it along. Sorry, did not have the exact mopar mag name in front of me or I would have included it too. It's still in the car.