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455 olds motor still in crate (1250 bucks) good buy?

juanblzer

juanblzer

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I have a friend who is selling this. I currently have a 208-700r4-350gmcrate combo. What are my options? Money is a concern. A good mod? A good buy?
thanks to all who contribute. /forums/images/graemlins/wink.gif
 
Unless the motor was complete, or you wanted to put it into an olds, I would say that that it's not worth it. From my own experience it takes a good bit of cash to build up an Olds engine only cause the parts are expensive and not always aval. I'm guessing that there will be some nice mods with the brackets and such. I would think that a bracket for the tranny would be the most obvious thing that you would need. I just don't know what you rides specs are.
 
Those engines ran a different bell housing pattern than the Chevy's did. You would have to modify a BOP (Buick Olds Pontiac) tranny to work with your transfer case. In 74 I think is when GM went to common engines in all the GM lines except Caddilac.
 
You'll need adapters to mate the engine with your motor mounts. These may be available from the aftermarket, but shouldn't be too hard to make. The tranny adapter plate costs around $65 and will let you bolt up your present trans and transfer case. But expect the 700R4 to die a horrible death soon after the swap. That 455 is a torque monster, even in stock trim, and a stock 700R4 will not be happy with that. /forums/images/graemlins/frown.gif
 
what if I buy a t-400? Is it hard to find an adapter plate to mate that tranny to an olds455? where do I find the adapter? Will my 208 hold up? or is a 205 in order?
Thanks for all the help! /forums/images/graemlins/laugh.gif
 
Juan,

You could buy a "BOP" version T-400, but they never made those in 4wd versions..... so, you'd have to have someone take it all apart and install a 4wd output shaft in it - which is basically disassembling the whole trans. /forums/images/graemlins/frown.gif

Yes, a 205 would be in order to handle the torque and power..... Then maybe it would be doubler time, eh - cuz your trans gearing AND case gearing would be much higher than you have now.... so you'd just 'bout have to double up!.... Would be a cool setup - but it would be costly /forums/images/graemlins/shocked.gif!

Marv
 
Juan,Like I said In the AZ forum....build an BB Chevy and You won't have to worry about the trans adapter.I would use the 205 case with all that torque.You're looking at alot of $$ to do either.The Olds motor is a heck of an torque monster(about 500#).You're looking at a new trans(TH400),trans adapter,motor mounts and the T-case.Parts are easy to get,NEW, for the Olds motor,but Expensive.If you want big block power/torque....get an BB Chevy.Don't forget about exuast issues.Mike
 
/forums/images/graemlins/smile.gif
Thanks for all the comments and replies guys. I guess I will wait for my current crate motor to get tired and then I'll save weight by just building into a 383 (at least I'll save some money) I really like my 700r4's 1st gear and I just had it built up. The motor is also only a 2000 model. Perhaps injection and a doubler would be in order (though my 208 is still running strong and a rebuild for it is only 500 including all parts and r&r)
 
You know that the doubler also works with a 208.
It's either 203/205 or 208/205, check their website.
But I guess everybody goes the 203 route because of the cast iron case. /forums/images/graemlins/thumb.gif
 
Wait a minute! I just looked on their website (offroaddesign right?) and see no mention of 208 w/205 for doubler. Am I wrong?
 
Sorry for the confusion, this is why I mistakenly thought about the 208 I was reading through it very fast and:
...
"A less popular auxillary method of attaching the NP203 to the TH350 is to use the TH350 with a longer output that was originally used with an NP208. You will use the 27 spline input in the NP203 to mate to this shaft and use the TH350 to NP208 adapter housing. This requires drilling and tapping new holes in the front of the NP203 to bolt it up in place of the NP208, and may require very minor machine work on the NP203 input bearing retainer. The drawback of the second technique mentioned here is that the factory TH350 to NP208 adapter housing is about 2.5" thick so your overall drivetrain length will be longer than using the factory 1" plate.

GM TH700 R4 / 4L60E Automatic Transmission:
The TH700 has the same bolt pattern on the back of the transmission as the TH350 and uses a 27 spline output shaft. Since the TH700 only came with the NP208 or later alum t-cases, it's shaft stickout is a little over 2" in factory form. One difference to be aware of is that the TH700 uses 4 metric bolts to secure the adapter to the transmission case.
There are two ways to bolt to the NP203. They are very similar to the TH350 mounting mentioned above.
1: replace the output shaft in the TH700 with an aftermarket output that sticks out of the case by about 7/8". This makes the output identical to the TH350 and you use a TH350 version NP203 with the 27 spline input and a TH350 to NP203 factory 1" thick adapter plate. This is the shortest method. The output shaft cost is $160 and it is available from ORD.

2: use the factory TH700 output shaft and the factory TH700 to NP208 adapter housing with a TH350 version NP203. You will have to re-drill and tap holes in the NP203 gearbox to be able to bolt it to the original NP208 adapter housing. You may also have to do minor machine work on the input bearing retainer on the NP203."...
...
Again sorry for the confusion.
 
Dude!!! Focus now... Say it with me... "I *NEED* TBI!" repeat this 100 times. That will make more difference in your ability to wheel than anything else except possibly a doubler (unless you can steal Marv's Marvel Mystery Q-Jet /forums/images/graemlins/wink.gif )
 
What's up with Marv's QJet? I and several others wish we knew. He says it's nothing special but it runs at angles that no other carb I've ever seen (well, except a certain Motorcraft 2bbl that is just as mind blowing) run at. There was one hill in Moab that no other carb could make it up. They all sputtered, choked and flooded, even qjets. 2 EFIs went right over (1 was mine), and then Marv gets up there, messes around a bit at a nose up angle that I believe I could have tipped him over backwards with one hand on his bumper, then goes on over the top like nothing but flat ground. Never missed a beat. No smoke, no sputter, nothing. Several of us strongly suspect that there is a TBI inside the housing and he just won't admit it! /forums/images/graemlins/laugh.gif
 
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