Few questions. Need to rebuild the front on my challenger Street/strip/grudge racing. Is it worth the expense to upgrade to hemi denny set up? or just a-arms, new bushings and good shocks? Motor has a dry sump as well.

No idea what your real question is. If the car is raced seriously then sure, you probably need a full race type suspension. A street driver or bracket racer or parking lot autocross can use OEM parts.

I'm puzzled as to how a dry sump and headers(?) already fit a stock suspension.
The small amount of weight saved with a MustangII IFS type "upgrade" can be found elsewhere,
Biggest plus is gaining space, most everything else is sizzle.

I think that set up is great. But probably not needed over TBs. if you need the room, that is a different story.

New motor combo and it has a dry sump. New headers will be built as well. Front end need redone/upgraded. Is it worth the 5k to buy a hemi denny fron or rks is what I am asking or go with simple mods, a-arms/shocks/bushing modify as needed.

The stock set up can be rebuilt for a few hundred, under a grand if it includes new t-bars and sway bars. Add some high end adjustable shocks and you may be at $1500. More aggressive alignment can provide significantly improve feel and performance over stock while having a system that has been proven for millions of miles.

For an additional $4k, you can drop 75-90#, you get quick springs changes, you get reduced turning radius, and get additional room around the oil pan. Just looking at the weight issue, you are paying $50 a pound to reduce weight off the nose. Fiberglass body panels provide a much better value. Springs changes, do you need to change springs for different track? Turning radius, depends. Extra room, that's always nice to have. Is all that worth an extra $4k? They do look cool, which is reason enough for some to justify it. Others will be impressed by it, which is worth it to some. It is lighter, which some people swear by.

I just bought an HDK(Hemi Denny) front suspension with power steering rack for my '70 Challenger. Denny was absolutely great to deal with and will text or email answers immediately. It's nice to free up all that space for headers, plus it just looks awesome.

I always found the stock torsion bars to be excellent for quick spring rate changes.

I would think so after subracting $4500.00 from your wallet.

Cheese and Rice, who falls for this? No one with off-road motorsports experience that's for sure.

Grizzly, can you define off-road motorsports for me please? I've drag raced my whole life and had a couple different 9 sec street cars. Maybe that's not enough experience for you?
My Challenger is a pro touring car with 4 Nitto tires and a 5 speed with a big inch Gen2 Hemi.
Using a coilover front suspension gave me room for all this to work, removed weight, added power steering, room for 2 1/8" headers, looks amazing and it handles like a cat along with bigger 6 piston brakes. So yea, I bought it because I wanted it.

curious on your thoughts on this system - also why did you choose this system over the RMS or magnaforce systems?

Prosport: Motocross. Anything can be fixed with stiffer springs in the front.

Grizzly, Motocross has absolutely nothing to do with my '70 Challenger lol, but I do love AMA Supercross and Motocross, never miss a race! I sure hope they find a way to finish the current SX season at some point in time.

Dangina, I LOVE the HDK setup, especially the power steering option.
HDK, Gerst, RMS, Tory Shellehammer, are all good high quality kits. Because of my custom reinforced inner fenders the only 2 kits that would fit my car are the Magnumforce and the HDK since I have to use the stock upper shock mount location. I am NOT a fan of Magnumforce so I went with HDK and his communication with me was amazing.

A dry sump system is difficult to fit in there with a K frame but the NASCAR boys used to do it so it can be done. Either way you're going to be doing a lot of fab work. Personally I'm not a fan of using Mustang II parts on a car that is a lot heavier than a Mustang II but it seems to work okay for drag racing. If the car was in my shop I'd start by mocking up the engine in the frame with the dry sump system installed and the see if a K frame will fit. If the K frame won't fit then figure out if you can modify it or if you need to switch to plan B. If you need to go plan B then you'll want to do a bunch of homework before ordering any parts since I doubt that anyone sells a bolt in system that is dry sump compatible. I helped a local chassis shop put a dry sump big block into a '67 Belvedere last year and that setup required a ton of fabrication. They ended up moving the engine over to the center of the car and rebuilding the entire floor in the car to move the tunnel over. It came out great but it cost the owner a boat load of money.