What's up with this 200-4R Nailhead adapter from Russ Martin?

[elagache]

Dear 65GS.com Nailhead experts,

Russ Martin has another item on eBay that has me puzzled.  It is an adapter bell-housing to fit a 200-4R overdrive tranny to a Nailhead:

https://www.ebay.com/itm/NEW-Transmission-adapter-Bell-Housing-364-401-425-to-2004R-overdrive/132841444709

It is a fancy piece of machining and quite expensive.  Okay I'm being ignorant again, but somehow I didn't think it was that difficult to fit an overdrive to a Nailhead.  Can somebody 'lurn me on this topic?

Cheers, Edouard 

[TrunkMonkey]

I spoke to Russell a while back about the 2004R. It will not bolt directly to a nailhead, (nailheads are not BOP) the adapter requires you to cut the bell housing off the transmission but the spacing is corrected with the adapter to the crank.

You also need a 4L60 OD lock up converter with 27 spline input. Hughes Performance item for about $550.

That puts you at $1400-$1500 plus the cost of the 2004R.

I like the manual, and I can get into Richmond 5 speed for about the same money as the 200R4 behind my nailhead.

[GS66]

I was looking at that adapter too, wondering about it.

[WkillGS]

I'll explain.... the Nailhead has a few inches of a 'bellhousing' built into the engine block, therefore the NH transmissions have a shallower bell. If you were to put a BOP or chevy trans behind a NH, there would be a gap of 3-4" between the crankshaft and the torque converter.
The first 200-4R adapter was from Bendtsens. It uses a long crank spacer between the NH flexplate, and a second 'flexplate' to bolt onto the converter! And of course, an adapter flange to join the different bolt pattern between the engine block and transmission. What you end up with is an extra long transmission with a goofy crank-to trans connector.

Russ's design makes for a shorter assembly and allows the crank/flexplate to bolt directly to the converter.

Another option for an overdrive is to put a Gear vendors OD unit behind the ST300 or ST400 trans. That ain't cheap either at $2700.

Here's the Bendtsens adapter. That crank adapter is a couple of inches long.

[elagache]

Dear Michael, Jim, Walt, and mid-60s Buick owners with an eye to newer technology, . . . .

Thanks for your replies! 

I'll explain.... the Nailhead has a few inches of a 'bellhousing' built into the engine block, therefore the NH transmissions have a shallower bell. If you were to put a BOP or chevy trans behind a NH, there would be a gap of 3-4" between the crankshaft and the torque converter.
The first 200-4R adapter was from Bendtsens. It uses a long crank spacer between the NH flexplate, and a second 'flexplate' to bolt onto the converter! And of course, an adapter flange to join the different bolt pattern between the engine block and transmission. What you end up with is an extra long transmission with a goofy crank-to trans connector.

Okay, thanks for the explanation of the problem.   I wasn't even aware of Bendtsens!  I just added it to my extensive collection of bookmarks.  Here is the link for anyone else who is pack-rat about this sort of info:

https://transmissionadapters.com/

Another option for an overdrive is to put a Gear vendors OD unit behind the ST300 or ST400 trans. That ain't cheap either at $2700.

Has anybody actually tried the Gear Vendor unit behind a Nailhead?  A friend of mine tried to put one behind the stock tranny of his 1957 Chevy Bel Air and was very unhappy with the results.  The shorter driveshaft resulted in some unpleasant vibrations.

I like the manual, and I can get into Richmond 5 speed for about the same money as the 200R4 behind my nailhead.

. . . .   I dunno'  Are you sure you want to be pulling a vintage travel trailer with a manual transmission? . . . . . .

Cheers, Edouard 

[TrunkMonkey]

I'll stick to touring all the sites in Kansas...   

[EZ Cool]

I have a gear vender OD behind the nailhead in my 50 Cherolet sedan delivery. Absolutely love it.

[Rollaround]

I have a gear vender OD behind the nailhead in my 50 Cherolet sedan delivery. Absolutely love it.

What is the GV final OD ratio?

[elagache]

Dear EZ Cool, Kevin, and 65GS.com information gatherers,

I have a gear vender OD behind the nailhead in my 50 Cherolet sedan delivery. Absolutely love it.

Thanks for the report!  Glad to hear that it worked out very well for your setup!

Cheers, Edouard 

[GS66]

The GV product must be tough since so many on Drag Week use it, those are some powerful cars. I?ve heard a lot of good things from people when on the Power Tour too, just none of them were behind a Nailhead.

[telriv]

The Gear Vendors OD is VERT STOUT. It's put behind 1200+HP cars, motor homes, etc. & best part can be shifted on the fly. WOT. Costly but in some cases worth it. Best part is that it CAN be removed & used on other vehicles you may own if you sell the car it was installed in originally & kept the original parts.

[EZ Cool]

I have a gear vender OD behind the nailhead in my 50 Cherolet sedan delivery. Absolutely love it.

What is the GV final OD ratio?

I just looked back on this thread and saw where this was not answered. The GV has a 80% OD. Not enough OD in my opinion but still much better than none. I would be happier with 70% but then it probably would not be as strong.

[TrunkMonkey]

I have one behind my nailhead (64 'lark with T-10 wide ratio and 3.54)

This was after looking at the cost for a 5 speed and as Tom mentioned, I could always use the unit behind anything I want, with only having to buy a correct tailshaft housing for trans type and the speedo sensor for gear specific gear ratios for it to shift at the correct MPH in gear(s).

It is a pretty easy install and simple to operate.

Before I was running about 3600 RPM at 70-75 and now it is about 2600.

And it is a hoot to drive around town, and being able to select over/under in any gear (especially 2-4) is touch of button rather than shifting, so it is fast and direct.

Digging and hitting the button on launch, it autoshifts to first and it really pulls hard and almost 30% further than 1st alone.

Driving around in 3rd over, is a bit higher than being in fourth, but "downshifting" to third while making the loud pedal flat will get about 30 foot of squeal and some wide eyes.

I am very happy with it, and the nailhead torque seems to be pretty happy no matter when or where I hit the button.   

(Yes Edouard, it would make pulling a trailer a delight behind the billy-goat, or just plain old fun hauling apples)

[GS66]

Thank you for the review! Tom make a great point too that you do not necessarily have to sell the GV unit if you change cars. I drive a lot so always been intrigued by the Gear Vendors. Might have to price one out while on the Power Tour in June.

[elagache]

Dear EZ Cool, Michael, Jim, and mid-60s Buick caregivers who appreciate modern conveniences,

(Yes Edouard, it would make pulling a trailer a delight behind the billy-goat, or just plain old fun hauling apples)

Thanks for the suggestion and thinking of my trusty wagon!  However, since Biquette has a Buick big-block I had more choices for transmissions and ultimately chose a hardened 200-4R from California Performance Transmissions.  What else could I really do?  After all, shouldn't a Buick built at the GM Fremont plant have a California transmission? . . . . 

Cheers, Edouard