I don't think Cummins Recon was building them in 97 so you are probably safe.

Are the heads posted above the heads that were on that engine?

Dwayne beat me to it ... Brianwo LOANED the heads for the build , I bought them from him after the contest was over and Sold them to Jim along with the modified intake and the Erson rockers that were set up on them.

Mike Doty did an outstanding job designing the port on that head within the constraints of the rules, which Parkhurst was nice enough to change mid contest after the spring pockets were raised so a longer valve could be used ... the way they should have been originally ... who is the rocket scientist at MP that thought it was a great idea to use stock length iron head valves in that head ???

The boxes are all ready packed up and on there way to UPS. I did send the boxes with the heads.

aah, the glorious stage 6. the mothership wanted stock length valves, and stock rockers, hence the ridiculously deep valve spring pockets and push rod intrusions. i was on a back order list for a set of those when they first came out, but the two years i was on the list gave me ample opportunity to investigate their foibles. i would (and did) pass.

What intake manifold? I suspect I know the answer already, though.

Yeah, right after he bought the bare heads from me. They were an oddball deal, too, since they had nice CNC'd chambers, but otherwise stock as-cast ports.

M1 single plane.

No, they were ordered shortly after getting the engine. I put them on a shelf and never touched them.

Slightly off topic, but has anyone ever seen an independant dyno test of a unmolested 575hp crate engine?
Depending on how the heads were prepped.... It seems like that could be a stretch.
I would think "some" amount of bowl work would have had to be done to get that combo to that power level.

The Stage VI-specific full-width (no valley cover required) 4150 flange version? If so, just a "heads up" -- no pun intended -- that is not a very good intake as cast from what I've seen.

Not that I recall, only the iron-head version that was rated quite a bit lower.

Here something I find interesting about the specs for the 505hp and 575hp motors.
The 505 motor is listed as 9:1 with flat tops, the 575 as 11.25:1 with flat tops.
The service replacement head for the 575 motor is listed as 90cc's.
At zero deck with a .040 head gasket and a 5cc piston, add 1cc for the area above the rings...... I get 10.66:1.

How much bigger does the stage v iron head have to be, and how far down the bore are the pistons to get that down to 9:1?
I guess I'm kinda surprised that they would have had different pistons being used in those two packages.

What kind of numbers did you see from the 505 test?

I just noticed a little footnote at the bottom of the specs for the 575hp motor.

"First quarter 2001 availability" and
"Requires a minimum of 110 octane racing fuel"

What I remember is the article was in either Hot Rod or Car Craft and that it was done at Dick Landy's shop. I don't recall it making much different than advertised, and considering DLI's connection w/ Mopar Performance, wouldn't expect it to for the purpose of a magazine article.

Anybody else recall that there were two (2) different versions of the MP 500 crate engines offered w/ Stage VI heads? The first one was rated at 545 HP, then IIRC they switched from 1.5 to 1.6 rockers and re-rated it to 575 HP. The rumor I heard years ago was that one of these "575 HP" engines was dynoed OOB at Ray Barton's shop... and wasn't even close to the advertised #.

If the heads used on the crate motors were similar to the ones you could buy over the counter, without some reworking, I don't see how they could have been making 575hp out of that combo.

Would have been "fun" to test one right ootb......eer.....oot-crate.

That's the one. Is there something better?

I went from an RB M1 4150 with spacers and an ootb Holley 850, to this 4500 M1 RB specific intake and a 1050.

The 4500 version of that intake is way better than the 4150. It has to do with how MP basically "stuck" a 4150 carb pad on an intake designed for a MW 4500 application.

Somewhere there are some pics of the Stage VI 4150 intake that the late Roger Helgeson reworked for me that shows how much he changed the transition from the carb pad to the runner entrances.

The only other choice is to use the RB intake spacers to enable running a standard RB intake with Stage VIs.

Sorry, I misunderstood, read the question. That is the intake that came with the engine.

my ports were no where close to MW, nor was this intake. Slightly larger than what they were born with. we only ground opened up the intake windows slightly on the intake and blended them back about 4-5 inches. I know all combos like different things, but changing to this intake and a 1050 picked us up .5 and 4-5mph over the RB M1 and spacers topped with a 850. I was choking the poor thing pretty good apparently. My combo was running the "go to" cam of the day Ultradyne NF69 .640.

never noted that Brad.... they pretty much did just stick a 4150 top on it. http://www.ebay.com/itm/NEW-Chrysler-Mop...=item25c880f302