Using 4wd for drag strip launch on a '77

I'm fixing the last point of frustration this spring by changing the rad (dropping in a Super Cooler from JBG) and hope to get to the track for some test and tunes in the summer. I've always used 2wd for runs because when I used to drive the truck in the winter and was on dry pavement you would get a loud bang once in a while from drivetrain bind, no problem when you have some slippage. I see the diesel guys use 4wd but they don't have my old style transfer case.

Would trying a 4wd launch be safe (not withstanding normal drivetrain abuse)?

Would a spool in the Dana 44 work alright? The rear is already spooled, the truck would only have the front hubs engaged at the track.

Thanks for you thoughts and help.

I'm guessing you're talking about drag racing on pavement?If so im sure the guys with the Diesels shut the 4WD off before they turn onto the return road.I have a 2011 F-150 Supercab 4X4 with EcoBoost V-6 and 3.55LS rear.My local track i ran a 14.68 at 93.7 mph launching in 2wd.I went to a different track and couldn't hook for crap in 2wd.I then put it into 4WD high and ran a 14.67 at 93.4 mph and shut the 4wd off before i turned onto the return road.With yours being the old transfer case i don't know if i would try it.IMO your best bet would be to get sticky tires for the back and some Cal-Trac bars and leave in 2wd.

Later Mark.

X2 what Mark said.

I don't know about the spool, but I'd try it out out a couple of low speed shakedown runs. I'd bet, worst case will be some vibration. You'll be the first to know

I never tried it on a dragstrip, but that was the only way I could get my 86 F150 Supercab street truck to hook on the bottle. 2wd was not an option at all on the street tires anyway. If I left on a 200HP hit in 4wd, @ 5600# it would MPH almost as good as the Banana in the 1/8. I had a 205 transfer case in it, and as long as I let it slow down a bit, all I had to do is bump the throttle and pop it back into 2wd. Never had an issue. But, 1 track here won't let 4wd's make a pass unless they're in 2wd only. But they're a bunch of chevy lovers anyway.

Thank-you for the replies, your opinions are valued. I omitted that yes it's pavement I would be running on. I have ladder bars so wheel hop is not an issue but I normally run 35's and with the 4.11 gears I'll need 32's in slicks so I'm not into the red at the end of the track. Doug, thank-you for the info. I twin sticked the transfer case if I ever twisted the rear driveshaft (fail safe to get home), so I have the option of popping the front axle into neutral before turning. Bind with the gear driven transfer case was my biggest concern but if you tried it successfully then I might give it a try. I'll be leaving with a 180HP hit.

Just a Doug said, a little blip of the throttle and the TC will slide right back in two wheel, been doing it for years on asphalt and anything else I needed to hook up on. I would have no concerns at all about the 205 but be sure to have quality joints and a balanced front shaft or things tend to get ugly fast. I do advise you make a good safety loop for the shaft paying close attention to the TC side as they have a tendancy to destroy transmissions and come through the floor pan nipping at your feet when they let go at high speed

IDIeselman wrote:Just a Doug said, a little blip of the throttle and the TC will slide right back in two wheel, been doing it for years on asphalt and anything else I needed to hook up on. I would have no concerns at all about the 205 but be sure to have quality joints and a balanced front shaft or things tend to get ugly fast. I do advise you make a good safety loop for the shaft paying close attention to the TC side as they have a tendancy to destroy transmissions and come through the floor pan nipping at your feet when they let go at high speed

I had a driveshaft crack a transmission this year, and put a hole in the floor board, I wouldnt put a spool in the front axle though, if one side hook's and the other dont it's gonna yank you into the wall, also if you break a axle shaft it will yank you into the wall, with a open front the worst that will happen is the front quits pulling

I was just talking with a guy in my class at the Frank Hawley school, he's running a GM Duramax 4x4 in the 9.40's and using four wheel drive to get there...... Said the truck leaves with the driver side front wheel off the ground @ 6000+ Lbs

IDIeselman wrote:Just a Doug said, a little blip of the throttle and the TC will slide right back in two wheel, been doing it for years on asphalt and anything else I needed to hook up on. I would have no concerns at all about the 205 but be sure to have quality joints and a balanced front shaft or things tend to get ugly fast. I do advise you make a good safety loop for the shaft paying close attention to the TC side as they have a tendancy to destroy transmissions and come through the floor pan nipping at your feet when they let go at high speed

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Thank-you, I'll get a driveshaft hoop built for the front first thing in the spring. Tight spot to work with, anyone have some pics of theirs? I could build one off the front axle like I did for the rear: