I'am building 71 pro street challenger , back half ,cage ,frame is done know its time to finish the front end.I can not make my mind up on which k- frame  to buy. Has anybody purchased either of these? wich one is better.

I have been looking at both and I'm leaning more to the Alterkation because you can use motor mounts with it and you have to use plates and ridged mount your engine with the Magnumforce, Also the Alterkation seems more streetable in its set up.  

wouldn't using motor mounts stress the block on a high hp motor? I have also thought a motor plate and midplate should be used for hard launching and high hp engines! Thanks for the input.  

I plan on more street time than strip time and the viberation from ridged mounting is very harsh on the car and driver. How ever if you are going all out and not seeing much street time goforit!!!!!! It's all cool!!

Mopar or no car!!!!!!

I have the alter-kation K frame.. It is a great piece... I have a power rack on mine. Bill ( the guy who makes it ) is a great guy and really cares about this product.. Also I know of a good many guys running this with lots of HP.. Its doesnt use biscut style mounts like stock but the schumacker mounts.. They aint going anywhere.. I'm running 700Hp ish through mine.. Its a beautiful thing. E-mail me at munneke@quest-tek.com if you would like pics....  

goat aint running it on the track so he dont need the weight savings of switching frames and rack and pinions. ive built a lot of cars with plates ,I use a 3/4 inch piece of tire cut to specs between the frame and bottom of 90 degree channel and run a standard rubber trans mount. I never felt any vibrations. no engine twist is a good thing and is simple to install.On a street car a rack wouldnt work very well unless you dang well best know what your doing before doing it, if your good in geometry it would help a lot.lotta factors to consider..  

Ive used elephant ears never a problem with vibrations. i kid try Moroso solid mounts  once went a block and back to the house to take them out have built afew B/Rb  Abodys with ears and sold afew sets never a complant.  

pro street? im making my dart pro street ,parts are on the way, a new rad,and a meziere waterpump,been 9.83 1/4 in this car. wtf does changing the frame have anything to do with making it work?,stock on mine with rubber mounts suffice quite well.on a street car wtf would anyone want rack and pinion? you want to make turns like a semi truck? different frame member and rack and pinion is race item in my book unless your going from front wheel drive to rear wheel drive and runnin dang quick, so quick that you need to lose every pound you possibly can.stock k-member bro ,why back half a mopar? you running in the 8s? sometimes I just dont understand folks.my car is borderline weekend warrior .read up 1971 dart for sale, which isnt anymore.take care  

also, the motorplate can be made into a scrolled piece of art. will work on any street or race car and raises thr oil filter from the frame a lil more, mine do anyhow. If ya run it on the street just cut the waterpump housing down 1/4 inch if your running the same belt system you had installed before teardown. manual steering here ,cutdown 69 charger column with a 90 degree  borgeson ujoint welded to shaft, the other end uses a set screw that fits in the groove of the steering box input shaft,lock it down tightly and gets rid of that crappr ,grease leaking mopar factory box .  

a tiny pipe cutter will slice thru the shaft easily.  

rubber trans mount allows the engine to twist a tad,no worries  

time usage or cycle life relieves engine stress, variances in temps relieves block stress, this is a good thing.  

sorry. time usage or cycle life reduces internal strength,more cycles, variances in  temps relieves block stress  

depends if you want to waste the money for the kit, I dont. take care