Hey guys, I've been out of the smblk Mopar engines for quite a few years now, I have a 1970 340 shortblock to build, no heads currently, I'm wondering if there's any aftermarket offerings aluminum or cast that are ready machined bolt on assemblies, or companies that offer built to spec remanufactured factory or aftermarket assemblies, my requirements are they appear externally like factory 340/360 castings, work with factory LA exhaust and intake manifolds and factory 5 bolt valve covers and retain the factory sparkplug angles, not interested in newer Magnum assemblies, I've searched the various vendors with little results and the assorted feedback on various forums about Aeroheads/Indy/Hughes seems iffy...I figured some here on Moparts might have some current purchase/use experience with aftermarket "factory/factory appearing" smblk 340/360 LA heads?

TIA
Mike G

Just a suggestion and hopefully its accurate. In 1988 or 1989 Dodge improved the 318/360 heads with a smaller swirl combustion chamber. Still an LA old school head but with a better CC. I looked up replacement heads on Rock Auto.com for a 1990 Dodge truck 360. Granted the intake valve will not be the 2.02" like the 340 magnum but for a price that can be changed. $349 each. Big block mopars have 440 Source for an aftermarket head that looks stock but small block have no option in LA offering.

https://www.rockauto.com/en/catalog/dodge,1990,b250,5.9l+360cid+v8,1073573,engine,cylinder+head,5304

The small block Trick Flows (aluminum) are supposed to be the best out right now. I believe they are completely bot on, except possibly the pushrods, which may need to be a 1/4" longer? I reference this from the Mopar Action magazine; they put a set on a small block build and I remember them saying they needed longer push rods. I am planning on putting a set on my small block too, but that won't be for quite some time.

Link.. https://www.trickflow.com/parts/tfs-61417801-c00
https://www.trickflow.com/parts/tfs-6141t784-c00

Looks like you can step up to 3/8" pushrods according to the text.

2nd link is for head w/ 10 degree locks and larger springs. There are a few options you can choose from.

Is Engine Quest still making LA heads?

"J" heads are everywhere Mike, you can probably find a set for less than $150. If you were closer I would let you have at all the ones I have stacked up.

2boltmain's suggestion on the newer swirl chamber head is a good one: less chance of detonation and a little more efficient.

But the real answer to your question would be to call one of the Mopar cylinder head specialists: I'm sure they have stuff that isn't advertised collecting dust and would be more than willing to rebuild them for you and do a "bolt-on" solution.

I think the ‘J’ head is a good option too.

All they need is hardened seats and they flow real good!
Anything aftermarket looks wrong on a resto car...

I got a pair from Aeroheads and they is superb!

Think you will have to go to ‘Mopar Madness of Colorado’ these days.

Limeyness

Note that the last of the LA head castings someone previously referenced were very different between 318 and 360. Only the 318 head "302" casting had the small heart shaped chamber. The 360 head "308" casting had the same open chamber as all the other production heads but a much better exhaust port. Both had "Swirl Port" intakes which is a fancy way to say that they had a massive pushrod pinch to allow for the bigger pushrod tunnels they needed for the angle created by roller lifters, it just happened to have a positive effect on intake charge swirling.

For factory look performance you're going to be limited to older W2 iron that still had freeze plugs and (I think) the Diamond cast aluminum W2s. Different exhaust port on the W2 but a lot of them have dual bolt pattern to normal LA manifolds and headers will bolt on but will have a port shape mismatch you might be able to lessen with grinding work. Also W2 require offset rockers and their own intakes. If you are trying to factory look there too they did make a dual plane W2 intake but getting hard to find.

No other aluminum head will look anything like a stock LA head.

I like the stock appearance myself, but you won't have any easy time pulling it off with any real performance part gains very easily or cheaply. Best of luck.

Well said Marcus Aurelius.

A lot of folks have been down the ‘look vs performance’ road...

A 1970 340 engine is the pinnacle of small block Mopar!
It deserves a T/A head really and then it’s the ‘bees knees’...

Otherwise it’s aluminum ‘all the way’ with some Trickflows...
Everything else is 50 year worn out junk in comparison...

Ps 50 years and three days...

Michael Ecks said: "Only the 318 head "302" casting had the small heart shaped chamber. The 360 head "308" casting had the same open chamber as all the other production heads but a much better exhaust port."

Ahh I did not know this.

Somewhat disagree. There was nothing magical about the T/A head as delivered, same J head used on any 360 or 1.88 intake 340, it just came with 2.02 intake valves and the intake pushrods moved over. The 308 casting has almost 30 years of engineering improvements, and is the best according to Larry Shepard. MP actually sold sets with offset pushrod holes like the T/A head for a short run. The easiest and hottest setup for OP, unless he wants to go down the W2 road, would be buy a set of 308 castings and plug the pushrod tunnels with something like brass rod and have them redrilled using the T/A head as a template. Then port out the entire pushrod pinch, have a shop run a throat cut on the intake side and open them up for 2.02 valves. Finally use the mopar performance porting templates to open up the exhaust ports and dow any final bowl blending on the intake side using same templates.

Hi MA,
I think you miss the point of the answer I gave.
It’s a 1970 340 engine...
The T/A head in the hands of Bob Mullen and others has been phenomenal!

There are many variants of heads and blocks, but there is only one year of 340 greatness 1970!

Me, I would just get a 408ci 360 short motor and put a pair of Trickflows on...

Or just go mad a get some Brodix heads, that will wake it up too...

Limey

I have put in 1.88 intake valves into the 302 heads. Using very good multi angle Serdi style cutter and minimal port match to stock 318 steel intake gaskets intake went 240 at .500 lift. The ex. port on those heads aren't good. they have the hollow floor/minimal short turn I put 1.60 ex. in them also. I want to say they maybe went 150 on the ex. I have the flow numbers in the shop.

The 308's have the much better ex. port, completely different, along with the larger better intake port. Sometimes larger machine shops can get /have certain re-manufactured casting number heads. You can request them. That's how I got a set for a 360 I built for my truck years ago.

Mike I would consider the Edelbrock 60779 heads.Summit Racing has them in stock. Hughes also shows them. If interested I would call them and make sure them can set you up with the correct springs for your camshaft. I also would ask them to verify guide clearance and valve seating.

Well I just arranged to pick up a complete 360 for parts this week, so it looks like I'll sink some coin into doing a set of J heads for the 340, a stock outward look is priority, I thank you guys for the suggestions


Mike G

Sounds like thats the only solution. I get it that the stock appearance is priority. Pay a good machine shop to do their thing and be done.

The ‘J’ head is as good as it gets in the early 70’s.

They all suffer with valve seat recession and cracks etc.
Most would go with crack testing before sinking too much in them...
We also have some with excessive internal rust issues from ‘shelf sitting’ in damp environments.

Best of luck with Mopar finest small block!

Agreed! The first dime to sink in heads or blocks is magnafluxing regardless of any known history