What GM transmissions clear the trans tunnel without cutting?

[JR]

Ok, so I expect to catch some flak for this, but I've decided to go with an LS engine for a while. But rather than get off topic with a debate of 440 vs RB, I'd rather just ask anyone who's been down the road for some advice here.

I'm doing the swap with as little cutting or modifying the body as possible, (so it's reversible) so I don't want to cut out the entire trans hump for a 4L80.

When it comes to overdrive automatics, are my choices 700R4 or a 4l60? I know the Silver Sport kit is a beefed up 4L60 with an RB adapted bellhousing, so I assume that one clears ok? I'm likely going to use an LQ9 for a base, and I want to end up with an install as clean as this one.

http://www.dodgecharger.com/forum/index.php/topic,117320.0.html


I'd strongly prefer an overdrive trans, but I'm open to suggestions or experiences here.

[chargerbr549]

I have been interested in doing an overdrive trans in the 66-70 b body platform and from what I have read about the only one that doesn't require modifiying the brace in the trans tunnel is the 700r4/4l60e trans (some applications you still might have to do some modifications to clear everything), some people have suggested 2004r's but the pan rail is still too wide where it needs to be narrower to clear the brace in the tunnel without doing modifications. As far as the argument of strength of the 4l60e in stock form it isn't the best but the aftermarket has alot of upgrades to take care of that issue.

Just a warning your going to stir up the hornests nest with the purists! LOL

[Mike DC]

  
I haven't run one, but a (beefed up) 2004r reads like the best 4spd OD automatic choice all-around.  Mopar or GM, the gear ratios, strength, ground clearance, rotating weight, etc.     

The 700/4L60E is known to be weak (even after beefing up).  And the gear ratios aren't as well matched as the 200.  It's not terrible but it's not really ideal either. 
 

[JR]

Good info guys, I appreciate it.

I really don't care what the Purists say, im over that stuff. Their tears bring me joy at this point, lol.

The gear spacing in the 4l60 is infuriating. I have it in my pickup, and while first gear and the O/D gear are perfect, the spacing of ratios in between is annoying.

The 200 and the 700 r4 use a 727 style kickdown linkage, right?

[cdr]

Good info guys, I appreciate it.

I really don't care what the Purists say, im over that stuff. Their tears bring me joy at this point, lol.

The gear spacing in the 4l60 is infuriating. I have it in my pickup, and while first gear and the O/D gear are perfect, the spacing of ratios in between is annoying.

The 200 and the 700 r4 use a 727 style kickdown linkage, right?

They use a cable

[c00nhunterjoe]

Do not waste your money on a 60. Without splitting hairs on a mopar forum, the 60 is weak no matter what you do to it and it will break in a lighter car and less torque then you are running. The 4l80 is the only logical way to do a gm overdrive trans but it wont clear a mopar tunnel.

[Mike DC]

  

Do not waste your money on a 60. Without splitting hairs on a mopar forum, the 60 is weak no matter what you do to it and it will break in a lighter car and less torque then you are running. The 4l80 is the only logical way to do a gm overdrive trans but it wont clear a mopar tunnel.

Are we talking about a hard-launching drag car or a street cruiser?  

A fair number of 4L60E conversions have been done.  I won't say I'm a fan of it but they can work in non-abusive settings.  GM put those things in some 5000-lb trucks & vans. 

[JR]

This is a street car with 9.5 inch wide low profile summer tires that sees 90 percent street and 10 percent autocross, and an 8 3/4 rear end.

It may see a drag strip once or twice a year.

Im not interested in launching it with drag slicks anytime soon.

[flyinlow]

My son's '70 Charger has  the 4l60 with the Silver state bell housing. (behind a 440) Only body mod was rolling the tunnel seam in a couple areas for more clearance.  Not sure if the stock Chevy bell housing would require this.
I like the LS engines ,but would not open my hood at a car show if I did that.

[c00nhunterjoe]

 

Do not waste your money on a 60. Without splitting hairs on a mopar forum, the 60 is weak no matter what you do to it and it will break in a lighter car and less torque then you are running. The 4l80 is the only logical way to do a gm overdrive trans but it wont clear a mopar tunnel.

Are we talking about a hard-launching drag car or a street cruiser?  

A fair number of 4L60E conversions have been done.  I won't say I'm a fan of it but they can work in non-abusive settings.  GM put those things in some 5000-lb trucks & vans. 

They burn up very easy in the pickup trucks and suvs. Im talking about daily driver street abuse. There are several built in flaws to a 4l60. Some you can bandaid with upgraded parts, others you can not. Just trying to prevent more wasted money here.

[c00nhunterjoe]

The trucks and vans that used the 700r/4l60 initially wer 175hp smog motors. When the ls came around the 60s were failing left and right. When the stock truck ls started to crest the 280 and 300 horse mark, they got the 4l80. The 60 just cant take it. You are going to dump a ton of money into upgrades for a "temporary" transmission as the 1st post stated. If this is a long term swap, then build  4l80, cut the floor out neatly and stick it in the shed. Put a modified floor in to fit the 4l80. If you want to go back to stock, put the old floor back in. It will be cheaper short and long term.

[Mike DC]

The trucks and vans that used the 700r/4l60 initially wer 175hp smog motors. When the ls came around the 60s were failing left and right. When the stock truck ls started to crest the 280 and 300 horse mark, they got the 4l80. The 60 just cant take it. You are going to dump a ton of money into upgrades for a "temporary" transmission as the 1st post stated. If this is a long term swap, then build  4l80, cut the floor out neatly and stick it in the shed. Put a modified floor in to fit the 4l80. If you want to go back to stock, put the old floor back in. It will be cheaper short and long term.

Do you have any thoughts on the 200-4Rs?  

The Buick GN guys seem to be able to make them live (with serious aftermarket overhauls).  GNs are medium-weight cars and those turbo/6 motors are nothing to sneeze at.  

[Mike DC]

           

I like the LS engines ,but would not open my hood at a car show if I did that.

The only vehicles that people want to see LS motors in, are ones that came with those motors from the factory.  Putting one in pretty much anything else will draw groans of disappointment.  



Somebody could probably make a buck selling fake dress-up air cleaners/valvecovers/etc to disguise LS motors as something else.    

[Kern Dog]

Ok, so I expect to catch some flak for this, but I've decided to go with an LS engine for a while.  I'm open to suggestions or experiences here.

Okay...FORGET this bullshit Chevy engine idea. 

[ACUDANUT]

 A LS chevy engine in a Mopar ?

[JR]

How well do the 700r4s/2004rs hold up, durability wise?

Do they normally survive in 4000lb, 400 HP vehicles? There are thousands of GM A bodies out there with them, so they must hold up ok, right?

Joe, I like the 4l80 trans, I just don't know if I can bring myself to cut out my original floor. I'm lacking the testicular fortitude to take the jump there.

[c00nhunterjoe]

The 200 is a much physically smaller trans. It is shorter then the 700/4l60. It is also harder to find and twice as expensive to build. Most of the gn crowd have snatched the usable cores up.

[chargerbr549]

If your going 700r4 route stay away from the earlier ones which I believe they started them around 1982, look for a late 80's to early 90's ones preferably ones that were behind 350's and then update those.

As far as durability of the 4l60e's I have a 96 Silverado with a 350 engine 4x4 with trailer tow package and and around 134,000 miles on the original transmission (which I know is a rarity) I tow with it on occasion and I recently installed a 383 to replace the 350 which I know most likely shorten the life of the trans but I have a spare trans laying around when that happens. I have also had several other mid 90's Silverado's with mileages in the 120000 mile range and both of them I had to rebuild the 4l60e's which tends to be the norm on a stock trans.

I wouldn't be afraid of going the 4l60e/700r4 route thats been updated with better internals but then I don't abuse my stuff either so most of it tends to last longer than other peoples stuff.

For me if I was willing to cut the crossmember area it would be a 4l80e hands down since 4l60e doesn't even come close strength wise.

[JR]

I would absolutely love the 4l80, but I'm just not ready to cut the crossmember or floor yet.

Any experience with the 4l65 or 70 guys?

My understanding of them is they are beefed up 4l60s from gm. I imagine they'd have the same durability as any aftermarket modified 4l60, but I'm just curious.

I'm not sold on a particular trans yet, I'm still learning the details. I'm not very experienced with GM drivetrain stuff.

[c00nhunterjoe]

I have not installed a 60 in a b body but a quick search on some other mopar forums has yielded that the 4l60 does not fit without modification to the floor either. It is not as drastic as a 4l80, but if you are worried about touching your origonal floor, you are going to have to take a sledge to it for the 60 to fit, and cut it out and remake the hump for an 80. In looking at photos, the 80 floor modification is not much worse then a 4 speed hump.
  The 65 and 70 series was the bandaid from gm until the 6l series was ready for use. It still wont hold up without heavy, expensive aftermarket parts changes. Just google 4l60 and performance and start reading othe people's 1st hand accounts of failure at low hp numbers. The most fully built to the hills 4l60 will still only handle  500 hp and it will not last. The drag race ones are only good for a dozen passes before needing full overhauls.

[chargerbr549]

On the 4l60e some of the fitment issues in the tunnel and crossmember when put behind a "mopar" engine are affected by how its mounted to the engine if its mounted by an adapter plate that will obviously move the transmission back however thick the adapter is and that creates problems and some guys have actually moved the engine forward to compensate for that which I don't think moving the engine forward is very desirable at all but for some people thats the only option.

If your using the 4l60e transmission with the removable bellhousing there are two different ones, the only one that you can use with the Quicktime bellhousing is the LS based transmission but the problem with that one is the bellhousing is about .750 deeper than the 350 Vortec style transmission because of the bigger torque converter and longer input shaft and once again it moves the transmission back into the tunnel and or cross member, not good.

The preferable one to use is the Vortec 350 based trans which I believe was used from 1997-2002 but nobody builds a bellhousing except for Silver Sport transmissions and they won't sell it by itself you have to buy the whole transmission setup which is big dollars.

So its no easy solution for mopar engine and gm transmission however using the LS engine and 4l60e trans together probably isn't as big as an issue since the LS engine is shorter overall than the mopar engine so moving it forward wouldn't be as big of an issue, plus the alot of the LS motors have aluminum blocks and heads so moving it forward won't be as detrimental for weight balance.

[flyinlow]

Silver State sells the 4l60 kit with three torque ratings. 450/550/650 ft.lbs. Do you need more than that? The body mod with a 440 engine is to peen the tunnel seam over at two and ten o'clock  .  Medium size hammer and touch up the paint. A LS engine might be able to move the trans forward and not have to do this.

JR ; do you have EFI?   If so instructions in the SS kit said you can use the EFI throttle position sensor to send a signal to the transmission controller instead of the hokey position sensor the kit comes with that we used with a carb.

[Mike DC]

                

Silver State sells the 4l60 kit with three torque ratings. 450/550/650 ft.lbs. Do you need more than that?

650 lb/ft?  That's pretty optimistic.  

Not all cases are equal.  A small block that winds up to that much torque at 4500 RPM once in a while?  In a 2500-lb car?  With little tires?  Yeah, that might work.  But probably not in a 440 Charger that weighs 3800 pounds and has decent tires.  

[Kern Dog]

My car is 3940 lbs and I run a 295 mm rear tire. I doubt the trans in my car ever sees all of the torque my engine makes because I peel out easily. If the tires spin, the trans never gets fully stressed.

[JR]

Flyinlow,:

Yes, I have efi currently. A Fitech TBI. Although I'll most likely use the stock LS stuff once swapped.