I am aware of the beehive springs available for the 392 engine. Since moving to the T&D rockers on my stocker 392 race engine, I have found out I need a better valve spring. I used the new 1515 PSI spring and experienced valve float at a relative low RPM (7000). Has anyone used a dual spring instead and what part number would that be? The PAC 1209X looks like it would work, but has anyone tried it or something close. Thanks, Dyno

I run the 1515 35psi and 8000 rpm no problem

I've been using PAC 1237X for years with no issues. It's a double spring. But, I also run a Solid Roller. Are you running shimmed or short travel lifters?

Steff, the 1237 PAC looks like what I need. Are you running a Gen 3 hemi? I have not been able to find a solid roller lifter to use. in my 392. I am using the 15820 Comp roller short travel hydraulic,. .060 travel. My first 392 uses the stock lifters and rockers with the Manley Nextek spring. It goes through at 7800 with no problem. I thought that using the Comp lifters with the T&D rockers would add stability to the combination, but something is not right. Like previously stated, the engine went into severe valve float at 7000 and hurt all 16 valves. I am trying to figure what component caused the problem. By the way, the T&D rockers are a piece of art. Thanks for helping. Dyno

Can you or have you tried running it with less preload? I would shoot for .010 to .015 hot
If not I would try it, it sounds like you got into valve float causing the valves to hit the pistons to me Are their witness marks on the pistons and valves? If so that needs to be taken care of to prevent future damages

I shimmed the short travel lifters solid was the only way to fix the valve float. I use the 1515 Pac spring but am using a Ti intake valve.

There are no solid lifters available. Yes, I have a 425" G3, NA. In 2014-15, I originally shimmed a set of hydraulic roller lifters and had a solid roller cam made. I also use the T & D's. They worked well, but, after about 3 years using them, I had a lifter try to twist and hurt a lobe. For my new cam, I was able to score a set of barely used Jesel Dogbone Solid Roller Lifters and they are leaps and bounds nicer than stock ones. The nicest thing I love about them is that the pushrod cup is sunk into the lifter body just above the roller. It greatly reduces the side loading on the lifter body, compared to the stock lifter where the cup is at the top of the lifter. I shift mine at 8000-8200 regularly with no float issues.

I'll just add my experience.

5.7/392
6.4 Apache heads, 1515ML springs, Ti retainers and stock valves
Originally used Factory lifters, now running Johnson lifters.

I've put nearly 1000 runs on this combo over the past 7 years, shifting anywhere between 7000 and 7800 with no issues.

Dual springs wont fit on stock heads

Look at conical springs.

What springs for 6.1 heads. Looking for cam and spring recommendations

Probably not relevant for theses Gen 3 type Hemi motors but I'm setting up the valve springs on my B1 motor (572 C.I.) that I'm hoping to make close to or above 1000 HP on the motor and feed it another 150 to 400 HP of NOS.
I have a 1400 lbs valve spring tester and the springs I'm using on these heads have between 340 up to 370 lbs. on the seat sand 770 to 800 lbs. open pressure at .700 lift. These springs would work up to .950 lift so they are not the best ones to use on this motor but they are the only set that I have on the shelf that will work, normally I would strive for .065 to .090 to coil bind at max lift at room temps (60F) with aluminum heads and take whatever pressures that gave me (usually within 20 to 40 lbs. max variances) this motor is for me so I'm going to use that as an excuse to learn if this is bad or good.
These heads have Jesel pair shaft 1.7 ratio rocker arms on them so I'm hoping that I'm okay with these pressures: luck:
These springs are used so I'm not exactly sure which brand and part number they were, they are 1.640 diameter dual springs with no dampeners, I'm planning on using pushrod oiling and spray bar covers both to help oil them enough to help keep them cool at WOT in the 1/8 mile
If you don't test you don't learn , huh

Steff, I ordered a set of the 1237x springs and hardware. The inner diameter of the 1237x spring is listed as .630. The standard Mopar seal and the Fel Pro seal has an outer OD of .665 What valve seal did you use that fits. The valve guide is .475 So the Comp 511-16 seal has the correct OD, but the guide size is .500 and will not work. Anyone have an idea or part number that would work? Thanks, Dyno

I found a VS 441 seal will work.