I'm in the process of building a 350SB - 400hp engine and figured I would just change the trans and diff.
I'm looking for a few suggestions so I can just have this all done at once when I have the new engine installed. I think 3-4k max.... I still have to see what my current diff is, but just assume all new...
Not interested in trying to reuse/save my old trans.

Sticking to an auto trans with street/highway appeal....

 

I don't have specific recommendations, but make sure you get an overdrive transmission. Also, you probably don't "need" to change your differential for a 400hp engine. Cheapest route is probably trying to get your diff rebuilt, but doing that is going to strain your transmission budget.

Z

 

I put a built 200-4R OD trans behind my 436 hp BP 383 in my 76. I also have a 3.70 rear.Love it.Mean on the street,cruize on the hwy

 

https://gearstar.com/gm-200-4r-perfo...ssion-level-3/
along these lines?

@gjohnson

 

I'm not a fan of low hp rated transmissions because the power ratings are often way over inflated. So the 200R4 is the easier swap, but has limitations that the 700R4 doesn't.

I would look into one of these with a multi clutch 9.5 inch TC. once you have an efficient TC the stall rpm is immaterial. I drove around for 20 years with a 3800 stall that had very little if any slip at cruising down the free way speeds. But when you floor it to Wide Open Throttle you are instantly up into the power range. I would ask about no kick down in 4th gear OD. That way you can go WOT at higher speed without it always doing a down shift

2004R – Precision Industries (converter.com)

2004R, 2004R Transmission, High Performance 2004R, 2004R Monster Transmission, 200-4R Transmission Heavy Duty Performance

 

Oh for the record I had blown two "High Performance" big block handling 700R4 with my little 355 ci. So I bought the best 800 or 850 hp handling 700R4 which was bullet proof and the most expensive 5 lockup clutch 9.5 inch converter which was a 3800 stall when put behind my 650 hp 427 SBC. 4.11 rear end and big slicks never hurt it!

 

Yeah, I want a plug and play with higher specs because I only want to do this once. Did you have to mod your drive shaft? Good stall for a street car? Getting my head wrapped around tranmissions now...

 

If by plug and play you mean whatever the tranny does as far as shift points, then you're ruling out a 4L60/80e. If you want some ability to fine tune the shifting, then you'd be into one of those. It will require a TCU and throttle position sensor.

My own mod was to go with the 4L60e and though having only a few hundred miles on it, I like it. The rear ratio is 3.54. My only real beef is that with the 4L60, which is a 700R4 just renamed, you have a very low 1st gear ratio, which makes for a quick shift 1st to 2nd and then a longer gap to get to 3rd. With the 3.54 rear end, coming off a stop at an intersection and just normal acceleration the car is into second before crossing the intersection. Others are quite happy with a set up like this and even with 3.70 rear gears. It's just a matter of taste really.

If you prefer a higher first and closer 1st to 2nd ratio, then the 200-4R if a good fit. It's an easier swap and can be built to manage a 400 hp/torque class engine.

In the end, since you stated you'd like street and highway appeal, just having OD will make a world of difference. My L82 had 3.07 diff and ran 2600 RPM at 60 mph. Now, even with a 3.54 rear end it runs 2100 RPM at 60. So, much better acceleration between the lower 1st gear and the rear end ratios, but 19% reduction in cruise RPM. Personally I think a 3.36 diff would be near perfect, that's a hard set to find for a Dana 44.

 

More/less something that can drop in without too many mods. i.e. driveshaft/etc. I was reading up on a few trans and how the driveshaft had to be cut short/etc. trying to limit the amount of wtf's might happen and cost creep.

 

I think you can use the same driveshaft for a 200-4R swap. Your 77, unless it was a L82, came with a TH-350. The TH-350 length with the tail shaft will be 27-5/8" if my sources are right. The 200-4R is 27-3/4. So, it would seem the driveshaft would fit. You might have to swap in a new U-joint as somewhere along the line they downsized them given the reduction in power. If yours was still using the larger ones you might need to get a 1310 to 1330 combo. Someone more familiar then me can comment.

I do know the mount is further back on the 200. I believe that can be accommodated by reversing the crossmember. I don't know if that will interfere with the exhaust front Y-pipe where it crosses over from driver's side to join the passenger side. But, I assume you'll be going to true dual exhaust if not already there, in which case, no problem.

 

I have new true dual chambered exhaust so the cross member should not be an issue... If I have to cut/weld it, I will.

On this site now and clicking the options... need someone to double check it for me...
https://www.monstertransmission.com/...l#.YYvhmk7MK8U

Torque Converter - No clue... on this... I don't need to punch it out of the hole, so will the 1650 work or go higher?
Torque Converter Perf Upgrades - Multiclutch billet - 900hp.... will spend few bucks here just to cover myself
Shift Firmness - Level 2
Case Type - chevy
Lockup - factory style lockup
Case Color (shades may vary*) - black
Speedometer - mechanical setup
Valvebody - auto.man
Pan Style - stock no plug... I might just add one or just get the alum with plug

Then there's the extra that will just take my money...

Popular Accessories (These have been Discounted for your transmission package!)
Forward Drum Upgrade Installed (recommended for 350ci-up engines) [+$575.00]
12 Qts. of Burn Rubber Brewery Premium Synthetic Trans Fluid [+$149.93]
TV / Throttle Cable [+$35.00]
Chrome TV Cable Bracket [+$19.94]
Fillertube & Dipstick [+$39.00]
Universal Transmission Mount [+$19.94]
Trans Cooler Kit #1403 [+$49.95]
Torque Converter Bolts (3) [+$9.99]
Universal Dust Cover [+$25.00]
2004R Aluminum Pan Stock Depth [+$299.00]
Transmission Flush - Dr. Tranny Kooler Kleen [+$19.98]

 

I did call monster as I was considering options. I'll state, purely my opinion and I could be off base, but in talking to them it just seemed like I was talking to a used car salesman in a plaid sport coat - technically, yes this is basically used car, but you know what I mean. Ultimately I went with Silver Sport Transmission as their kit for the 4L60e came with almost everything needed to do the swap. But in your case that's not an option as they don't have 200-4R's.

You might want to checkout Bowtie Overdrives. They provide good clear explanations of what comes in their different build levels. They also have what appears to be a good bracket to aid in getting the TV cable set up right. I can't speak to their ultimate quality. But I suspect if you do some searches of the forum you'll find some posts.

 

Things have really changed since Marc 2020 and the shut down.

 

https://shiftsst.com/blog/post/1968-...ctfit-kit.html

https://www.bowtieoverdrives.com/cat....php?ITEMID=13

going to compare all these and see what's best. It's probably apples to apples to oranges, but hope I can make a good decision here.

appreciate the help....

 

If I was to build a vette that for some reason had to have a 4 speed auto OD tranny and it had a up to 400 hp 350 class motor. 700r4 and 460, require a 29.5 inch drive shaft and a modded crossmember for tail shaft mounting. At least that's what mine had. I wanted thing simple and me being in control. So I bought a lighted 50 amp switch and mounted it near the steering wheel on the dash. very reachable even with my 5 point harness on. It was on/off tranny lockup. Even with the best 26 vane racing pump and multi clutch TC the lockup clutches can NOT withstand shifting into gear with that gear in lockup. Like shifting into 4th OD while it's in lockup. I actually bought two shifting governors. one 5000 rpm and one 6500 rpm for race days. At WOT it always shifted right on the governors setting. You can buy them for what ever rpm you want

I actually drove around for two years and 15 - 20K miles after I smoked my lockup clutches while driving something over 150 mph and going to WOT. What I found is that highly efficient 9.5 inch TC's specifically designed for your motor output work just fine with no lockup function. Not like yesteryear when I had a 3000 stall in my 67 dodge charger 440 R/T which always slipped to 3000 rpm unless you actually went faster. I think it was something like a B&M street fighter or saturday night special.

But anyway if was me all over again with this 400 hp 350 class motor. I would buy the highest HP range 200R4 within the persons budget. Forget the lockup function and all it's associated hardware. Contact Precision and get a 3000 stall 9,5 inch for the mild 350 TQ. IMO I personally started with a 3.55 rear gear and my 700r4. I sat down with tire diameter/rpm/mph calculators. I didn't need some moronic 3.08 rear end that on paper would be going 280 mph at red line in OD and lugging in OD just going 1700 rpm at 80 mph. I wanted below red line at my peak hp at a vette doable speed right at my class limited 175 mph for the local open highway timed road racing events. 4.11 is my rear end and on paper still a potential of over 200 mph at the rev limiter. I found 3.55 gear in OD to not work well. I've always told people that 3.73 or even 3.90 is the best with up to 6000 rpm motors

Vigilante – Precision Industries (converter.com)

Performance Transmission, Racing Shifter and Torque Converter Car Parts Catalog (cpttransmission.com)

 

My 200-4R is from Bow Tie Overdrives. Works as it should