First when i put the 455 and th400 tramsnmission in, it had about 3 inches left of the yoke showing and about 4-5 inches before the engine sat down on the mounts and also the back of the transmission pan were hitting the back of the oil pan. Also, the motor mounts are at the rear the frame(where should they be) should i move them up? Then i put the th350 one the 455 but driveshaft of course too short. Took it back off remounted the th400 and slid the cross member back a few holes and moved the engine mounts forward and lowered the engine all the way down and it looks like a tight fit and won't sit all of the way on the mounts :ball: All i need is for it to get down in there and i can hook it up. I can't wait to do some upgrades (eventhough it is a good engine) because the guy i bought it from sold it for 750 but he torched off the exhaust bolts so i have to overcome that obstacle too. He left it in so that i could hear it run and not one puff of smoke and purred like a kitten original miles 72,000 out of a '75 electra so now i've been reading up on things about this engine. ray:
Hi, Did you happen to read this article? Lots of great info for your swap: http://www.buickperformanceclub.com/conversi.htm
OK, from what it sounds like you are going from a Th350 and Buick 350 to a Buick 455 and th400 right? For an easy swap do things one at a time.... Swap in the Buick 455 with the th350 attached and make the engine mounts work. This will be the correct placement for the engine even if you do swap the th400 in later. It sounds like your issue is you are trying to use a th350 driveshaft with the th400 and that is not going to work. In order to keep things simple without getting a custom driveshaft either find a th400 driveshaft or just use the th350 trans. If you have the trans in the correct location then the engine will end up where it has to based on that. :TU:
You are exactly right! I have the driveshaft for the 350 but he guy gave me two for th400 an long one and a short one (hopefully one will work) but get this.... Okay so today, i go back under the monster and measure the motor mounts for the 455 then for the 350. The mounts for the 455 is wider than the 350 so i need the brackets for a 455 of which they sit on. So i called the guy i baought the engine from and he's putting them in the mail today. My guess would they are wider to fit properly snug insde of the mounts and maybe a lil shorter in height because the 455 has a lil extra girth, you think i maybe right? Also thanks for the response.
next time let us know what you are planning to do and we can tell you how to do it:TU: Yes the frame pads need to be swapped and are tough to change... Be patient with that part. By the way, this is a good time to change the front coil springs... The extra weight of the 455 engine will make the car handle and brake strange if you do not swap in the 455 springs. Also either find a 455 fan shroud or go with an electric. Good idea to get a 455 rad or an aftermarket rad as well.... I am pretty sure the throttle cable needs to be swapped as well for the 455. if you do go with the Th400 trans you will have to modify the e-brake cable, move the cross-member, and add a kickdown switch under the gas pedal. This is one of the reasons I suggest leaving the th350 in place for now and make that swap to the Th400 another project.
Check to see that you are using the rear 2 mounting holes on the engine block. There are 3 on each side and you will use only 2 . there are two locations for eng mountings on the 430/455's and make sure you are using 455 mount pads. the big buicks used the forward 2 mount holes on the engine block and the skylarks use the rearward 2 holes which will moves the engine forward on the mounts about 3-4 inches. if the pads are correctly set they hang over the front crossmember a little. good luck. been there done that. Lots of driveshaft combinations in skylarks, you need to match year of rear to year of driveshaft. pinion length varies year to year and transmission type to transmission type, you may need to shorten driveshaft or find one the proper length. I have ameasurement chart if you have year of rear axle and year or paint marking stripe colors on driveshaft.
Geeeeesh well while i am at it i might as well go ahead and do the th400 because once i am done with it i'm not messing with it anymore. As long as i know how to do it, it should be that big of a deal, right. This info is very, very helpful. I didn't know any of this but i am going do it. Thank you sir. ---------- Post added at 08:07 AM ---------- Previous post was at 08:00 AM ---------- The rear axle is 1972. I really appreciate all of the info that you guys are sharing with me. They say that when you help people, it come back to you and lord knows that's what i'm known for most is helping people,though i don't go around bragging about it like lots of people. I just love doing it. Thanks to everyone who has chimed in. :TU::TU: ---------- Post added at 08:17 AM ---------- Previous post was at 08:07 AM ---------- if you do go with the Th400 trans you will have to modify the e-brake cable, move the cross-member, and add a kickdown switch under the gas pedal. This is one of the reasons I suggest leaving the th350 in place for now and make that swap to the Th400 another project.[/QUOTE] this is what i need more info on as to what i need to do to modify the e-brake, move the cross member to where? and what to do and how to add a kickdown switch under the gas pedal. I don't have a lift but only four jack-stands and it's up on all 4 of those now so that's why i said i would rather do everything now even though it may be hard complicated or time consuming. I'm grateful for the love here in this community too:dollar:
Move the crossmember back on the frame, the holes should be there. Install Anchor part number 2268 trans mount....different than a TH350, buy the correct E-brake cable from E-brake handle mechanism to crossmember, buy correct intermediate cable that goes from x-mbr to each drum, have correct torque converter cover, shorten driveshaft to 54.25", install yoke for the front. While you have the drive-shaft out, install new u-joints and get it balanced.
Fellas the input here has been very informative, so let me ask you this?? I was starting to be doubtful that i had made the right decision on getting this 455 out of a '75 Electra 225 with on 71,000 original miles on it. Was this or will this be worth the swap and will i be looking back saying "man that was no big deal"?
Nothing wrong with the 455, it will make a lot more torque than the 350 and thats what you want for a street car. If you want more performance down the road, swap on some heads from a 70 455 and that will increase the power. Okay, I looked back and found your old posts. So you are working on a 72 Lesabre and the engine is from a 75 Electra. The 72 lesabre is a B body style and the 75 Electra is a C body. You are in pretty uncharted territory with this swap as 99% of the info and advice you will get on this site is about the 64-72 Skylarks and the 455 and th400 swaps with those years. I do know that when people take an engine out of a 75 Electra the engine mounts and frame pads do not work in the chassis of the 64-72 cars. In my mind the th400 swap will be way more hassle than the 455 swap. If you try to swap them both at the same time you will not know which holes in the frame to put the frame pads into. My advice to you is to leave the trans in place, if it works fine. Not many people drag race and beat on 72 Lesabres so I am guessing this is a street car. If you are not racing this car then why not leave the th350 in place and not have to move the trans crossmember, not have to mess with the e-brake cable, etc etc. There is no performance advantage to the th400 for your car. Furthermore if you leave the trans in place then it will be easy to sort out the engine frame pad locations on the frame. Simply bolt the frame pads to the engine mounts on the engine, lower the engine in place, mark where the frame pads need to be on the frame, remove the engine, bolt the frame pads in place where they need to be and then drop in the engine for good.
Yes sir. I needed that. i don't know much about the kick down cable, i don't even know how it looks but tell me what you think about this piece that i found on ebay. what does anyone know about this? http://www.ebay.com/itm/GM-TH400-TR...Parts_Accessories&hash=item43b6882484&vxp=mtr
the frame pads from the 75 electra will bolt directly to your 72,use your turbo 350 tranny,bolt the frame pads down on frame drop motor in and you dont have to mess with crossmember driveshaft anything.make sure your flexplate is drilled for a 350 torque converter.mine wasnt.
