TH400 Adapter Plate

[tarra]

I have an old TH400 adapter plate from when Jeep starting using the TH400 and didn't use their own case.

Can anyone tell me if any regular GM Th400 will bolt up to this?

I have heard years ago that they used Buick/Olds TH400's and to find one of those. But its been so long I cant remember if that is true or not.

Thanks

[jeepsr4ever]

It uses the old buick pattern (not the BOP) and wont fit the chevy.

[tufcj]

Yep, The adapter ring was used with a Buick "nailhead" TH400, NOT the BOP pattern. There was also an adapter or spacer ring for the crank that is needed.

Best bet is a 74?-79 Wagoneer that had the AMC patterned TH400.

Bob
tufcj

[dbesade]

Yep, The adapter ring was used with a Buick "nailhead" TH400, NOT the BOP pattern. There was also an adapter or spacer ring for the crank that is needed.

Best bet is a 74?-79 Wagoneer that had the AMC patterned TH400.

Bob
tufcj

OR the 76 to 79 CJ7's which also had them ;)

-Dave

[ironman_gq]

why was it called a nailhead?

[tufcj]

Buick "Nailhead V8"

Buick first generation of V8 lasted from 1953 through 1956. It was an OHV/pushrod engine like the then new Oldsmobile "Rocket V8" engine. This engine became known as the "Nailhead" for its unusual vertical position of its small sized valves - that looked like nails. The Nailhead V8 family employed a camshaft with higher lift and longer duration to offset the smaller sized valves and arguably restrictive intake and exhaust port areas. The small size valves and intake runners made for engines with a lot of torque with many exceeding the 1 ft-lb per cubic inch, which was exceptional for the day.

264

The 264 in¬? (4.3 L) 264 was a direct replacement for the 263 straight-8 in Buick's large cars. It was produced in 1954 and 1955.

322

The larger 322 in¬? (5.3 L) 322 was used by Buick from 1953 through 1956, primarily in 'senior' series cars.

Nailhead V8

Buick's second variation of this V8 was also named Nailhead. It was produced from 1957 through 1966.

364

Apparently the smallest displacement Nailhead, the 264, was dropped when Buick introduced its new small displacement V8. Buick, like most of its competitors, continued to expand their durable V8 engine to larger displacements such as the 364 in¬? (4.125in bore)x(3.40in stroke)=(6.0 L) 364.

400

The next member of the family was the 401 in¬? (6.6 L) 400. This was actually a 401 that had been redesignated a "400" in order to meet GM directives for maximum displacement engines in mid-size cars.

Another Buick "400" engine was a member of the 400/430/455 family and was produced from 1967 to 1969.

401

The 401 in¬? (6.6 L) 401 was Buick's muscle car powerplant of choice, and was found in the company's Skylark Gran Sport and Buick Wildcat, among others. As unlikely as it seems, the air cleaner for the engine is annotated with "Wildcat 375" "Wildcat 410" "Wildcat 445" these inscriptions indicated not the in¬? but the ft¬?lbf. of torque produced by the engine. The "Wildcat 410" was the 2-barrel carburated engine that was standard on the 1962-63 LeSabre. The "Wildcat 375" was a no cost option on the 62-63 LeSabre that had lower compression to run on regular fuel (another Buick V8 had "Wildcat 375" written on its air cleaner but it wasn't a "Nailhead", it was the 4 barrel version of the 66-67 small block Buick 340). The "Wildcat 445" had a single 4 barrel carb. It was the standard engine on the Invicta, 1959-66 Electra, 1962-66 Buick Wildcat, 1963 Riviera and 1965 Riviera (the 64 and 66 Riviera models had a 425 in¬? engine with a single 4 barrel carb. named "Wildcat 465" as standard equipment).

In an effort to overcome the "restrictive" exhaust port design, Buick enthusiast drag racers in the sixties adapted superchargers with a custom camshaft to feed intake air in through the exhaust ports and used the larger intake ports for exhaust outlets. Perhaps this feat of ingenuity, and the unusual appearance of the engine modified in this manner, also intimidated rival racers and added to the Nailhead V8 legend that lives upon this page of US auto history.

425

425 in¬? (7.0 L) 425 This was the largest version of the "nailhead". It began as an option in 1963 on the Riviera and it was later available on the Wildcat and Electra models too. The 1964 and 1966 Riviera had the 425 engine as standard equipment. 4 barrel carburetion was standard on all 425 "Nailheads" that were called "Wildcat 465". The "465" sticker on the air cleaner did not denote engine displacement as many though, it denoted the torque rating. It was possible to order two 4 barrel carbs, which were delivered in the trunk along with the intake manifold and installed by the dealer. This version was called "Super Wildcat" and it was standard on the 1965 Riviera Gran Sport and the 1966 Wildcat GS.

Custom nailhead pic: http://www.rodandcustommagazine.com/...905/index.html

Bob
tufcj[/code][/url]

[jeepsr4ever]

Wildcat...I like the sound of that!....meow

Those werent bad engines though

[fifesjeep]

We had a 69 Buick Electra in the yard over here with the 401... Not a bad motor from the factory... mid 300hp, mid 400ft-lbs of torque... 10.25 compression ratio... I called my old man and he told me to grab it if all looked good... for his Grand-sport project... I removed the plugs turned it over by hand and figured alright that's a start... jumped underneath it yanked the pan and caps... everything looked mint... Even the oil residue was clean... Well, the yard passed "you have 45 minutes, finish and come to the front"... So, I said it's a good point to stop... put the caps, pan and plugs back on... Left the yard, came back at 2pm.. and there was two crusty guys with the picker... they took the tranny too Worst part was telling my old man... So, I told him he can have the 455 that was in my 68 442, yeah I know a Buick motor in an Olds... (I have a 425 built with a nasty lope and it's an Olds motor ) Too bad it's in NY collecting dust... Anybody have a decent house with a huge garage they want to dump off for cheap in Va???