Alrighty gents, got a fun bench race for ya.
Just got my 383 back from the machine shop after poking it to a 438.
The 383 originally had the COMP 288R-10, Eddy RPM OOTB Heads, M-1 and a Holly 750 DP. Made 399.6hp to the ground at 6300rpms. Loved everything about the motor. Had 40k street miles and countless laps (road Racing and Autocrossing around the West Coast). I would drive the car hundreds of miles to the events.

Car got a little bit of attention.
https://www.motortrend.com/features/ccrp-1112-dan-weisharr-1968-plymouth-roadrunner/

So new engine has a full 440 source rotating assembly and my builder suggested a cam company and Morel lifters , so I told him I wanted the cam to behave EXACTLY the same, just take advantage of the increased CID.
New Cam is 254/258@.050, .630/.623 Lift on a 103/111 centerline.
Seems greedy and weird, but I guess we'll see.


So I've gotten to the heads and I'm not sure what direction I want to go. I'd like to stick with OOTB as much as possible with a spring swap. I really like the idea of the CNC'd Stealths for the stock look, but I like the idea of the trick flows, but the 440 source guys mentioned there was shrouding or valve clearance issues on the 383's?

So whatcha guys think? I don't need a million HP, as this car is in a class and by the weight and tire I won't need more than 475rwhp, but I would like to turn it up a touch when I hit a hill climb at altitude again.

The shortblock is unpainted and on the stand, so plenty of time to pivot if needed.

There are others that have put the Trick Flows on a 383 with no problem, either get your heads ported or sell them & get some TF's, that said I make NO promise they will work on a 383 bore

The last shop I took my Eddy's to sat on them for a year and went out of business during COVID. They're gone.

THAT sucks, here is a guy that put TF heads on a 383
CLICK HERE FOR LINK

Good lookin' car and nice article.

FWIW, I have 2 383s. One is .06" over with stock stock. The second is .03" over with a 440 crank. I have two sets of 906's. One set has 2.08/1.74 Manley valves. The second set has Ferrea 2.14/1.81" valves. I have run both head sets on both short blocks. No notching of bore required.

I doubt any would be required for your 434ci, and if it did it would be minor. This is assuming TF placed the valves at the same spacing as the 906. If you're at 4.31" of bore and TF says you need a minimum of 4.32" that closes the cylinder closer to the valve by .005" with the smaller bore. That's a sheet of paper!

If the TF 2.19" valves do interfer then taking a few thousandths off the valve would be insignificant to the valve job and easy to do. Hell, I've done it a drill press with a flat file and some emery cloth.

For half the money you'll spend on a new set of 240's you could probably get the RPMs cnc'd and/or port finished real nice. Many seam to have forgotten the RPMs are a pretty good head. With that said my first choice would be a set of 240s or even 270's if you're willing to twist it a little higher.

Trick Flow 240 heads right out of the box.

I would put the 440 source CNC ported heads on in a New York second

Watching that Engine Masters episode the other day on this very subject shed some light on the difference with all these heads mentioned

I don’t believe 440 Source has offered the Stealth heads CNC ported in quite some time.

Not that you couldn’t buy the heads and have a porting service do them up.

I had a customer looking at buying some Stealths and called about them the other day.
He was told they didn’t expect to have any for quite a while.

I think many heads(and a lot of other things as well) are going to be bought based on availability.

Well that's lame. I just spoke to them a couple of months ago and they said that they had them in stock. Stuff is flying off the shelves these days I guess. I have a set of their standard stealth's on the shelf I was saving for my street 440

A couple of months ago they head cnc ported heads? Or just heads?

I haven’t seen them on their site in a long time.

Edit- well I guess I need to take that back.
There is still a listing for the CNC heads, but when you click on it, it brings up cyl head hardware.

I know at one point they seemed to be having trouble with the porter.
Maybe that’s all been resolved...... or perhaps they found someone else to do them.

We did do a batch of a couple hundred of the CNC heads and they sold out in weeks. We are doing more, but don't expect them to be here until probably March or April of next year. We've had shipments that arrive at the port and spend 3 months sitting on the ship before they are even unloaded. So who knows when anything will be back in stock.

Lets go Brandon!

So, who's doing the porting ? Are those ported after they arrive in the US, or do they arrive that way from overseas ?
Last set I got I had my guy work on them, just curious about a future set.
(In my case, for this project stock-appearing is more important than absolute max power.)

Indy SR1

I just completed a 383/496 combination with ported Stealth heads (purchased used from Rick Gorski). Ordered a custom Bullet cam, Edelbrock Torker intake, exhaust manifolds setup for a 68 Charger. Testing it with exhaust manifolds on the test stand, I have to say it was the strongest sounding engine (including ALL makes) that had exhaust manifolds. Sounds badass. Haven't driven it yet as I am waiting on the transmission.

We were out of them for about 3 years because we sent Bob at Modern Cylinder head a pallet of 50 heads to CNC port for us. The 3 years passed as we kept waiting, thinking and "hoping" we would get them back, and then customers started telling us they were buying our heads directly from him, so he was selling the heads and pocketing 100% of the money for himself. We even offered a reward if anyone could get the heads back, and we had a couple people go to his shop and demand to see and/or collect the heads, and they were just given some kind of excuse and sent away. Likely all the heads are long gone now. So once we gave up hope on that, we had to find a new 5 axis CNC shop, which we did. In a few more months we should have them back in stock, and from that point there should be regular enough production runs that we won't normally be out of stock again.

What a bummer. Glad to hear we'll have some options in the near future!

I know quite a few peps that have had issues with Bob ripping them off, POS Thief his whole life from what I have heard.

Can you get on the list for a set of CNC ported Stealth's?