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-   -   Will It Hook Or Did I Build A Drift Rig? (https://67-72chevytrucks.com/vboard/showthread.php?t=767162)

dirtfarmer22-250 07-09-2018 05:24 PM

Will It Hook Or Did I Build A Drift Rig?
 
I done some trading last winter and ended up with a fresh rebuilt 71 model 454. I don't know much about the motor except it's got domed pistons a aluminum intake, and a 850 holley on it. It has 049 heads that looked like they came from the machine shop yesterday. I had it running on a stand and water leak around the valve stem seals so I pulled that head off and had it fixed. That's when I saw the domed pistons. The cam has a really steep ramp. I used the Kwik Performance serpentine belt set up. Got it put together and it sounds amazing. Instant throttle response.

All that said, the truck I put it in is a RCSB 91 GMC. A fresh 350 trans with a shift kit and stock converter (for now). Right now it's single tracked with I think a 373 gear. What am I going to have to do to get it to hook up? I don't plan on taking it to the track but I would like to bust on a Mustang or 2. I'm use to messing with 64 to 72 chevy truck and they hook pretty good on drag radials but this is a new deal for me.

Sorry I kinda rambled on there. :smoke:Any suggestions, tips, tricks greatly appreciated. Thanks in advance..

weq92f 07-09-2018 06:25 PM

Re: Will It Hook Or Did I Build A Drift Rig?
 
A posi would help! LOL.

Those domes are not unusual with #049 open chamber heads, even the semi closed chambers have domes sometimes. That thing could have compression anywhere from 8.5:1 up to 11:1 depending on everything else inside it.

Drive it like you stole it!

-klb

dirtfarmer22-250 07-09-2018 06:59 PM

Re: Will It Hook Or Did I Build A Drift Rig?
 
That's the plan. I got the motor for next to nothing so it should be fun for a while. Who know's, it may be more than I'm expecting. I've got my eye on a 427 just down the road from me too.

Captainfab 07-10-2018 12:15 AM

Re: Will It Hook Or Did I Build A Drift Rig?
 
It sounds to me like you may need a stall converter, depending on the specs of the cam.

With a leaf spring rear, you are going to have to address spring wrap and wheel hop. A set of Cal Trac bars will help with that. And of course the afore mentioned posi unit.

dirtfarmer22-250 07-10-2018 12:58 PM

Re: Will It Hook Or Did I Build A Drift Rig?
 
That's the direction I was heading. Already started looking at posi units and was wondering if there was a specific GM truck to be looking for to find one or just buy new? A friend of mine has a wrecked 94 4wd diesel and I believe it's a 1/2 ton, I'll have to look at it again though. Would it be worth taking the cover off to check or should I go another direction. I know a 3/4 ton isn't for me.

Captainfab 07-10-2018 11:32 PM

Re: Will It Hook Or Did I Build A Drift Rig?
 
To my knowledge the only factory posi available in a '88-'98 1/2 ton is the Gov Loc AKA Gov Bomb. I wouldn't waste my time with one with what you are doing. That '94 4x4 may have the 9.5" 14 bolt, but it will be 6 lug. That would be a step up from the 8.5" 10 bolt that is likely under your truck. You would just have to source some 5 lug conversion axles for it. The early '90's 454 SS trucks had the 9.5" 14 bolt.

dirtfarmer22-250 07-12-2018 09:48 AM

Re: Will It Hook Or Did I Build A Drift Rig?
 
Is there a easy way to tell what the 14 bolt is or do I have to tear it apart to see what it is? If it's the one I need, I'll have the axles filled and drilled. I had a mopar 8 3/4 done a few year ago and it worked really good for me.

Captainfab 07-13-2018 12:14 AM

Re: Will It Hook Or Did I Build A Drift Rig?
 
It is really easy to just pull the cover and see what it inside.

DieselSJ 07-13-2018 01:19 PM

Re: Will It Hook Or Did I Build A Drift Rig?
 
Quote:

Originally Posted by dirtfarmer22-250 (Post 8299597)
Is there a easy way to tell what the 14 bolt is or do I have to tear it apart to see what it is? If it's the one I need, I'll have the axles filled and drilled. I had a mopar 8 3/4 done a few year ago and it worked really good for me.

Look at the cover.

9.5" -
http://www.differentials.com/wp-cont....5-14-Bolt.gif

10.5"
http://www.differentials.com/wp-cont....5-14-Bolt.gif

dirtfarmer22-250 07-13-2018 02:00 PM

Re: Will It Hook Or Did I Build A Drift Rig?
 
Thanks for the info and pics. I'll check that out this afternoon.


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