Seems as if there are alot of questions about sp (400) on this forum. Well I have a couple: 1) Is it correct that Buick used an SP400 from 65 to 67 on 300 or 340 engines?o No: 2) What extension housing lengths were used on SP400 transmission with the above engines?:Brow: 3) Will a full size Blazer (before S10 blazer) transfer case bolt to a SP400, or do I need to get new mainshaft and extension housing from Blazer or Jeep? :3gears: Thanks again:laugh:
Sorry, I can only answer question (1) with some confidence. First, the correct terminology is Super Turbine 400 or ST400. The ST400 only showed up behind a small block if you ordered the heavy duty "LeSabre 400" option (usually for better towing capacity). The rest of the ST400's came standard behind the big nailheads from '64 (an odd duck to say the least, usually to be avoided), '65 and '66, and one year behind the 400/430 in 1967. Hopefully someone will correct me if I messed this up, it's the best I could remember on one cup of coffee. Devon
Devon: Thanks, I think you answered one of my questions that kinda works for me. I forgot the 400/430 in 67, which should be a BOP pattern. That is what I am looking for. If it is a BOP then it should bolt to the 300/340 engines (not necessarily work with flywheel/converter though). Questions 2 and 3 go hand in hand, I think. Probably going to need to replace the mainshaft and extension housing with 4x4 replacements. Wonder if ST300 SP converter could be used on ST400 with SP? (Think the terminology is correct)
Yes, I run a ST300 converter in my ST400. The one inch smaller diameter is good for a little more stall. Devon
The ST400 was used behind the 340 in the 67 Sportwagon 400. This is consistent with the previous posting referencing the '400' options.
Thanks for the info. I will be putting the ST400 (sp) behind a 300 buick. Of course I will update the valve body for one with 3-2 shift valve.:beer No one out there with transfer case question answers?:spank:
First, I'm not quite sure what must be done to the tail end of a pass car 400 to adapt to a transfer case, but if it's any consolation I've swapped output shafts and output housings between ST/TH400's in the past with no issue, so I doubt there is anything unique about the ST400 that would make it any different than adapting a later TH400 in the same manner. This also came up in a google search, but I'm not sure if the info is useful to you: http://www.jalopyjournal.com/forum/archive/index.php/t-83670.html $0.02, Devon
Yes you can put a Blazer transfer case on the back of the 400. You will need the output shaft, adapter plate, and transfer case from the blazer. The only trick is to find one with a th400 in it. Most of the Chevy's came with th350's behind them and the th400 setups are fairly scarce and pricey. Good luck. Mike
Mike, the real question is wheter or not the ST400 conversion is any different than the TH400 conversion? Devon
Nope, it's identicle. You have to watch the wire for the sol. on the pump when you pull it but the back ends of them are the same. I have done a couple of these for guys over the years and I think there is still one in my dads J10 with a 455BBB in it yet. Mike
Thanks Mike and Devon for your inputs. Now all I have to do is find one of them there Blazerian's with a TH400 and 4x4. CRAIGSLIST, EBAY anyone. Hey maybe the HAMB can help me.:beers2:
There are a few things to keep in mind. First, there are two different transfercases available for the TH400. One is a NP203 (chain driven) and NP205 (gear driven). There are at least 2 different styles of NP205 mounting configurations. It would be best if you bought it all bolted together to ensure everything is compatible. As silvergs72 stated, the TH400 setups are quite pricey. A lot of the 4x4 guys are using the front portion of the NP203 tcase to create what is called a doubler. A good resource for your 4x4 questions is www.pirate4x4.com, some good information on the doubler is here: http://www.pirate4x4.com/tech/billavista/Doubler/index.html. It also tells you what applications to look for. Good luck
I have a BOP TH400 mated to a transfer case out of an '86 suburban. Great condition. I don't know where you are, it's for sale. You could do a switch-pitch conversion (solenoid, front pump, case plug, etc.) fairly simply since it is out of the vehicle. I don't know if a suburban transfer case will fit your Blazer. The Suburban used to be powered by a 455, and then a Cadillac 500. (That's for sale too, if you want it, if you can handle the torque!) What a great combination for moving a big truck. -Bob C.
Bob: I am interested in your setup, but I am in Kansas. PM me with the details (how much). We can discuss this matter offline. Thanks
Hi I'm bobc's brother. The trans/case was actually in my suburban. I had a transmission shop do a HD rebuild on the TH400 of the suburban, and swap the bellhousing for a BOP bellhousing so i could run my 455 in it. It has about 30,000 miles on it, but worked fine. It is still mated to the transfer case. I hate to guess at the number, but I think it's an NP208 transfer case. It's whatever the stock transfer case from the '86 3/4 ton suburban is. I got rid of the suburban 3 years ago, but couldn't part with the trans/case setup, because I just knew somebody else would want to do this! I'll let my brother bob handle the shipping estimate, he's good with that stuff. Drop me a PM and I'll send you a picture or two, we can work out the details. -Derek
you dont have to find a blazer to find a th400/transfer case. the 73-87 pick ups, and up to 91 in the blazers and suburbans. mostly in the 3/4 and 1 ton trucks. transfer case options were the np203 full time case, np205 part time case, and np208 part time case. the most common and fairly strong setup is the th400/np208. the strongest setup is the th400/np205 which is one of the strongest transfer cases ever made. chevy used mostly 208s in the later years. 205s were also used all the way back to the 60s maybe even earlier but i cant remember for sure. if you have any more questions let me know, 4 wheeling is my passion so i know a thing or two about it. good luck:beers2:
