I've heard a 401/425 Nailhead will bolt up to a Jeep. Is this true? Does anyone know what the deal is? HHHMMMM....Jeep wheelies at the deer lease. :Brow: Thanks, Rick
i know they did have a 401 and their tranny was the same bell housing as a nailhead. so i would think it is a buick. i am not sure, but some one here will know.
The Buick Nailhead had a 4.19 x 3.64 bore and stroke, the 70's AMC 401 engine had a 4.165 x 3.68 bore and stroke and it wasn't a Buick Nailhead. The Buick "Dauntless" 350 CI V8 engine was used in 1969 and 1970 J-series pick-ups and Wagoneers .
I posted the same question over on a Jeep forum with no answer yet. Would be cool to have a 401 with 2x4 torqueing on the 4wd. Rick
Some early 70's Jeeps did use the Nailhead trans case as it had a 'short' bell so an adapter could be used to mate it to the Jeep engine. I have seen some CJ's with nailheads on eBay. That sure would make a great combo!:TU:
If some early Jeeps had a nailhead then there is a possibility of it working. BUT, the bell housing pattern for the 350 buick is not the same as a nailhead, and all the jeeps that I have seen with Buick engines had either a 225 or a 350. [1968 up]
The Dauntless Buick 225 CI V6 was introduced for model year 1966, used in C101 and CJ models. First year for the Dauntless 350 was model year 1969.
Hi Guys, There is an "Urban Legend" out there that seems to persist about the AMC 401 using a Nailhead bolt pattern 400 and it just ain't so. The Jeep has the starter on the right side, the Nailhead on the left. The rear of the Nailhead partially covers the torque converter, the Jeep 401 does not. Just look up Turbo 400 on ebay, and if there is a Jeep 400 and a Nailhead 400, you can compare and see the obvious differences, although it's probably nothing that some machining and welding and fabrication couldn't fix, but in stock form, no way! Tim
I believe Jeep used 3 different TH400's. The early stuff was Nailheads with factory engineered adapters onto whatever engines they were using. Jeep owned the V6 tooling and rights with the 225 V6 dauntless from 67 to 75, but instead of updating the bellhousing flange they kept the BOP-C. Jeep also purchased the 350 Buick for sometime which also used the BOP-C case. The final variation was the AMC pattern TH400 as used behind the later AMC motors. Jeep also used the 2.8L GM V6 for a few years before coming out with the outstanding 4.0L I6.
CTX-SLPR, I think this is how the "urban legend" keeps going! There is an AMC THM 400 over on ebay right now, check it out. I have been through a number of junkyards and have compared the Nailhead and AMC THM 400's and while slightly simular, they are NOT the same bell housing. I have asked about this "factory" bell housing adapter that AMC had "used", and no one can come up with even a picture of one, let alone an original article! So for me, for now, until proven wrong, they aren't the same and no they won't fit! Tim :Comp:
The 401 amc engine aint eaven close to a 401 buick engine. The same cu. in. is just a concidence. AM used Borg Warner/ Ford transmissions thru the 60's if that gives a clue. Ford starters also. But ac delco ign systems. there was a lot of ''brother in lawing'' between Amc/ Ford. The amc 401 more closely resembles the International v8, in that it is bulky for the engine size, the v is wider, the heads and block is more massive than most of the era. The 401 had the oil pump in the front coming off the t/g cover/ 75 psi system.
