Kicking the idea of doing a 440 cube Gen 3. Has anyone done one with any real world numbers preferably track results. I am really impressed with my 426 6.1 based deal and looking for an all out NA Gen 3 deal to put in my 65 Coronet super stock clone.

Has anyone seen good (> 600whp) results out of a street car, pump gas stroker?

My disappointing 449 dynojet run is attached.

Five years ago I hydrolocked my 6.1 Magnum motor. I replaced it with a 449 Mopar aluminum block (4.185 / 4.08" bore and stroke) with the biggest Thitek heads, a ported 6.1 manifold and 2" Kooks headers. Recently I completed a manual swap (Tremec Magnum) and added a larger cam (237/249 0.57/0.58").

Coming from the LS world, I'm very disappointed in the power. Especially as these heads are said to outflow almost anything LS-based. Granted I'm knock-limited to 18-20 degrees of ignition timing (11.6:1 compression; I would have preferred 11:1) on 93 octane. There may be more power with more timing; I'll know when I try E85. These heads have also always let a good bit of oil by the seals. Probably not much at WOT to drop octane, but who knows.

My 90 mm Arrington throttle body seems to limit me to ~98 kPA at 6500. So while there's a few ponies to be had with a bigger TB, it's not a lot. My Legmaker 4" pre-TB intake doesn't appear to be a restriction at all.

HHP told me they get "mid-500s" out of their street car 426 strokers. Again, not great.

I'm wondering if the intake manifold (ported 6.1) is the cork. It's certainly not the dual 3.5" exhaust, which was originally built for a Hellephant I'm not going to be able to get. Can the potential of these motors be unlocked without an extremely tall intake?

From every thing i've read the long runners in the 6.1 intake will be holding you back a lot in the higher rpms .
The more vertical angle of a G3 Hemi port makes it hard to design a low profile race intake, without ending up with the runners too short.

Are curved runners no good?

The above motor saw oil starvation on the road course, so we pulled it. I'll be looking to get it rebuilt, and when it goes back together I hope to have a plan to make 600+ NA whp with it. I've given the intake manifold to a mechanical engineering buddy of mine to CAD up; we hope to 3D print some different intake designs to try. The trouble with the high-rise stuff is of course hood clearance on a modern street car.

Any suggestions on where to send the motor? I think the crank is ok, but the bearings don't look hot. You can catch your nail on some parts of the bore. Thanks.