Has anyone posted about this topic? I was wondering about using a newer GM or T5 behind my nailhead for my '31 ford coupe. Any info or do's and dont's would be greatly appreciated. I am new to this and was just wondering. The nailhead is the JT code with the (supposed horsepower rating of 325) Thanks in advance for your comments!!!
www.v8Buick.com The real problem is getting the fairly rare bellhousing and flywheel for the 364/401/425 nailhead. I believe that bellhousing has the standard GM trans pattern, so any GM manual trans should fit (Saginaw, Muncie, T-5 for examples)
T5 behind a nailhead is asking for trouble, unless you keep skinny tires on it so it just spins the tires when you punch it hard. Even the 5-speeds they put in the bigger trucks have had problems, but might be okay with that motor in a much lighter hot rod.
Not a problem at all... They are available brand new these days. Bendtsen's has them. The problem I would see is putting 450 ft. lbs. of torque through one. Depends on how you drive. If it hooks up, say bye bye...
The Tremec TKO 500 rated at 500 ft/lb of input torque or the TKO 600 would both be better choices than a T5, plus all the options like eight different shifter locations, ratio choices, both electric and mechanical speedo hookups etc.
Unless you run a real short gear out back, you won't be starting out in first much. -Lee Atomic Radio www.atomicpinup.com
I was lucky 3 years ago to score a '66 Skylark GS bell housing on e-pay. I modified the clutch fork bar and made the linkage connect to my '48 Ford pickup brake/clutch pedal assembly in my deuce roadster build. That's a fresh Tremec 5-speed bolted to the bell housing. My '64 Riviera 401 just came back from the machine shop and now it's time to marry everything up and try to fish the steering column past the left side Sanderson header.
Yeah that'll make a mess in the driveway the first time you pop the clutch. With all of the torque these motors make, in a light car such as you are building, a set of 3.23:1 gears and a regular 4spd would do very well.(iron T-10, muncie m21-m22 ST10 even an iron saginaw would be stronger than most T5) The gears will keep the rpm down some and yes, the bellhousing adapters are available new now. There is one in the classifieds right now.
Man you guys are awesome! All this info I have never even thought about. I guess I need to research some more or bite the bullet and get the Tremec. I will be driving the wheels off this thing and wanted some sort of overdrive for it. 35 Woodie, that motor is looking good!! keep us all posted. Thanks again to all of you for your thoughts.....it's much appreciated.
Check out the Tremec T 3550, 500 or 600 as well as a T5. A stock 302 Mustang will shred a good T5, think what a torque monster nailhead can do!
I love this. More T5 for me. Stock 302 haven't shredded a "good" T5 yet. Perhaps early T5, or abusive driving (sidestepping clutch at 6K with traction), but not even "aggressive" street driving. The late-model Mustang crowd generally uses T5 until about 400-450HP, then switch to TKO. Many will switch earlier, but just as many successfully run at these power levels. How stout is the Nailhead? How will it be used? What car is it in? Tires? Etc. - T5 will live very happily behind a Nailhead depending on usage. A Nailhead is also capable of breaking a T5. It all depends on usage. For strong, low-end engines like your nailhead, this is not a bad option. Well, the Camaro WC T5 is avail with 2.95 first gear & Mustangs use 3.35 first...both very reasonable ratios for a manual trans first gear, so I think you might be basing your opinion on the NWC S10 units that have a 4.03 first gear... Lots of info geared primarily toward flatheads & T5 in the link in my sig line, but much info transfers across...
450-500hp 302s still don't make the 445lbft of torque the stock 401 Nailheads make. Zman said he ripped a mount for his rear loose from the frame and I personally destroyed one set of trailing arms and then later a complete Olds rear housing not to mention a th400 with relatively mild motors. Sidestepping a clutch at high rpm isn't abusive driving. It is how most cars accelerate the best, so long as it holds together. This is what has kept me from putting in the LaSalle box in the 55 so far. However, I think the iron case T10 is on the list for this year. Don't confuse high rpm motors like SBF and SBC with big torque motors like Buicks, Olds, Pontiac, Caddies. Big torque motors can do a lot of damage to parts that big Horse power motors can't break.
I tried running a Saginaw 4 speed behind my 401 in my fenderless '36 Dodge and tore up 1st gear- rebuilt it and took out 3rd gear on a hard shift. Conclusion? If you drive like I do go with something at least as heavy as a Muncie. Rodshop
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