will J heads work on a 318? And many many more questions.

[J-MacsMopars]

Well, since no one seems to want my J-heads, I am thinking about using them on my 318. Are there any mods that I would have to do so that they will work? Thanks. Jeremy

 

[cudaspaz]

Someone correct me if I'm wrong, but did not most of them come with J-heads.

 

[J-MacsMopars]

J heads were on 71-72 360's and 71-73 340's.

 

[Cheapstreet]

you can use them no problem..
too large a int valve...may get shrouded by teh cyl..wall..
but...thats really only getting picky....
cheapst

 

[stroked 340]

Jeremy,my friend put a set of 1.88/1.60 j's on his "smog" motor 318 this past season,had the head's surface cut .060 and with a .477/.480 cam he's gone in the 13.80's with it in a '70 dart...

 

[SublimeDusterSK]

+1. they will work just fine, a slight loss of bottom end is well worth the gain of top end. IMO. note the comp ratio will most likely drop slightly due to the larger 72cc chamber volume. only the 273 has interference problems with intake valve and cyl. wall. 2.02" and 1.88" valve will clear without trouble on a 318. good luck.

 

[J-MacsMopars]

Thanks guys. Sounds like thats what I am going to do. I hope it runs good when I'm done.

 

[66fs]

Your only problem should be, that you'll have to beef up everything behind it.

 

[trbodrt]

i put 360 heads with 2.02 valves on my 318 and it runs fine. I just had the heads milled to bring up the compression a little.

 

[MopaR&D]

+1, make sure you use taller pistons or mill the heads a decent amount to bring compression up to a reasonable level.

 

[J-MacsMopars]

So, if I choose not to mill the heads, would it be better to keep the factory heads? My engine is a 1969 318 with 70K orig miles.

 

[rumblefish360]

That's what I would do, use the 318 heads but use the 360 valves.

Now, what else is done to the engine? What is the taget goal?

 

[J-MacsMopars]

I am not building this one to be a race car. I am however using a crower beast cam and I am debating on weather to use the Weiand Stealth or Edelbrock performer intake. I will be running duel 2.5 exhaust with an H pipe and a 904 with 3:23 gears. I am hoping for a dependable driver that I can have a little fun with. I have the J heads, so I figured I would use them.

 

[rumblefish360]

Whats the cam specs and the compresion ratio? AKA stock bottom end?

 

[J-MacsMopars]

Not sure of the ratio now, but the cam specks are 269/282 adv 480/494 gross. That is what I was told from the person I got it from.

 

[oldkimmer]

.............Thats 2 much cam, and do not use the J heads, they will lower ur comp 1 full point.......it may run decent, buy will b slower all the way around.......get some 302s............kim.........

 

[J-MacsMopars]

Would I be better off with a Edelbrock performer cam?

 

[340dart.812]

what size valve are in your j heads? the 1.88 would work better but with stock pistons they are too far in the hole to get the compression up to be able to use the cam you have if you change the pistons to some zero deck you would be able to maybe use that cam and the j heads if you milled them you should be able to sell them for as much as you can get the later 318 heads for or you can find the magnum heads cheap for your stock bottom end and pistons the eddy cam and closed chamber heads it will run grate lots of torque probably 260 hp and 350 ft lbs my guess

 

[J-MacsMopars]

I have a set of the 1990 318 twirl port heads.Are they the later 318 heads you are talking about? I have the whole engine. It was a throttle body injected with the roller lifters. Would those be better than the J heads?

 

[mopar340dave]

Good reading here:
http://www.allpar.com/mopar/4bbl.html:read2:

Fairly accurate except the piston availability comment for 318's. You can get anything you need nowadays.

 

[mopar340dave]

Yea, for your purposes.

 

[340dart.812]

ya ya those are the ones you want. those are the same chamber as the magnums if i remember right or darn close use those and clean the bowls up and port match them to intake and try a smaller cam your stock pistons are in the hole like .120 the performer might be a good cam but I would look into the smallest comp thumper they make a reg hyd flat tappet cam for us mopar guys now it closes the exhaust valve earlier and helps build compression and gives you the sound of a larger cam they just dont like to rev real high like past 5800 but you shouldnt need to rev yours up that high anyway also what intake are you running

 

[mopar340dave]

More good reading:
http://www.squidoo.com/Mopar318?utm_campaign=direct-discovery&utm_medium=sidebar&utm_source=ThomasC

 

[J-MacsMopars]

I have two intakes to choose from. A weiand Stealth and an edelbrock performer. I would buy a different cam, but I am trying to use what I already have.

 

[mopar340dave]

Either is fine...I kinda like the stealth...does it have a little bit more top rpm???

P.S. Just checked..Weiand dual plane Stealth intake manifolds feature long, separated runners for bottom-end and mid-range power, plus a special runner design and larger plenum to flow the air needed for high-rpm horsepower. They mount single, square-mount 4-barrels and make power from idle all the way to 6,000 rpm. That makes Stealth manifolds the perfect choice for your street/strip vehicle.



the performer is done at 5500...the stealth pulls higher