Wheel Hop

What is the best way to cure wheel hop on a 69 340 swinger. There is a stock pinion snubber on the differential (sure-grip)

A copy of the old direct connection rear suspension manual will do the job. I'm sure others will chime in with their recommendations, but the beauty of the mod's in the manual were pretty much unnoticeable which = $$ while street racing back in the day. Worked well at the strip as well, especially with slicks

The best way to stop wheel hop on a Mopar is to find the problem. Your car was not prone to wheel hop when new and everything in good shape. In fact, Mopar went to some lengths to prevent wheel hop by the very design of the leaf spring location unlike any of their competitors. You can start adding aftermarket parts or you can get to the root of the real problem. But that probably cannot be done on the computer. You will likely need someone who knows a bit about Mopar rear suspension to diagnose your problem.

Better set of new Hi Po rear leaf springs
Sounds like you have the original 5 leaf 318 or smaller motor springs on the car, yes?
Even if they are the original 6 and 7 leaf factory H.D. springs they are how old?
Buy new good ones

As already stated, wheel hop wasn't much of a problem on Mopars, especially the HP models.
That said, springs, bushings & shocks do wear out; the only good 50-year-old springs I've had were the B-body XHD "Hemi" springs.
The rest all settled quite flat, even my early B cars.
Under what conditions, what power level, etc are you experiencing this ?
I'm not sure how cheaply you want to address it, but you could start by clamping the forward leaves.

The car does have the original 6 leaf springs on it and they look pretty flat. What would be the best replacement springs to get closest the the originals.

Springs &Things, aka ESPO, is one source if you don't have a local good spring shop.
I've been happy with them on a couple cars, got + 1".
They can make them stock, + 1", + 2" if desired.
On another car, I cannibalized a pair of SS springs I had laying around, and mixed together they worked fine.

"most" springs were designed to be almost "flat" at ride height.
there are a bunch of ways to fix your problem, depending on how much money you are willing, or wanting, to spend.
over the 50 years i have been working on these things, the first item i check are the spring and shock bushings.
after that, i have found if you have a spare set of springs laying around or can find a set someone has replaced cheap, chop the eyes off of the main leaf, and install that leaf under your original main leaf.
then clamp the forward leaves together. use bought or home made clamps as you see fit.
the ride is not adversely affected, and wheel hop disappears.
just one way i have done it on the cheap, but keep in mind, i NEVER throw anything away, plus i have tons of shop tools here at my disposal.
your mileage will vary, depending on your stash of "stuff" and your tool kit.

Try calling Greg at Tri City Competition in SO CA for a good set of H.D. leaf springs
His shop is near Carlsbad, CA, not in Carlsbad. Sorry for not having a phone number for his shop
His Son has his old shop in Michigan, it is on the internet under Tri City Competition, maybe he can help you also

My Ebody has the factory 340 suspension with front and rear sway bars, decent gas shocks. It’s a 4 Speed. When you really get after it there was some hop. An extended pinion snubber cured it. Even dumping the clutch at 5000 with slicks. State of the art, nope. But it doesn’t hop anymore.
Doug

An adjustable snubber will definitely help and possibly even stop it all together. But there was a lot more involved in getting the car to "plant" the tires. That is where the rear suspension manual would come in. if you're just trying to eliminate the wheel hop, start with the adjustable snubber

[Greg Luniak in Calif. 760-630-9094

Now I would start with a shock update to a basic single adjustable like the Rancho RS9000 series. They have a pretty stiff rebound that will keep the tire planted
Gus

When my '69 Barracuda 340 was about 4 or 5 years old, wheel hop started on aggressive acceleration, so I took it to a spring shop, and they installed an additional leaf, 2nd layer, making 7 each side. Problem solved, and as a bonus it raised the rear an inch or two which I thought improved the stance and looks. The springs are still working as intended, no hop.

My recommendation is to add a 2-1/2" wide leaf to each side that is 54-1/2" long with center hole 19-1/2 from the front end and see if that fixes the wheel hop. This could be relatively fast, cheap, and easy. I believe my extra leaves probably came from a junk yard, because they were hand cut to length by torch. Photo shows the extra leaf in 2nd layer.