Greetings, It's great to run across this site. I need some advice from people who know. I have an '84 LeSabre with an olds 307. I've had the car since '89 and the engine finally gave out. I'd like to put in a 455. Questions: What sort of modifications to the front end would I need? What about air conditioning, would it need to be removed due to a new engine configuration? Would the existing transmission handle the larger engine. As for the 455, what would be the best , but not the most expensive way to increase the HP? I'll be starting this project late summer, and the car will be put out to stud as my weekend cruisemobile. During the week I'll be driving a battleship grey Caravan. I feel so dirty admitting that. Thanks, Alex
Hi Alex. You will need new springs on the front at least. The Buick 455 is light as big displacement engines go, but heavier rate springs were used. What is the tranny? I am using a TH350 behind my engine at present, no troubles. It was rebuilt to handle the torque, but my original (abused) TH350 lasted behind that 455 from 1990 to 1997 and when it went, it was reverse that wouldn't work. Tranny had over 200K miles on it at the time. The 455 should really have a TH400 behind it, but you can use a 350, many guys run quick quarter mile cars with the TH350 with no trouble. It's lighter than a TH400. A search on the various 455 forums will get you plenty of info on a powerful rebuild. Heads are key- there are new design aluminum Stage 1 heads available from TA performance, but they are expensive. However, they are popular enough that folks are selling their ported iron heads, and maybe you could get some cheap? Worth a look in 'parts for sale' .:TU: Also carburetion is pretty critical- you'll want at least an 800 cfm unit (such as the stock Q-Jet in most cases)
I have a couple ideas for you. 1. Put an Olds 455 in it, you should be able to use your existing motor mounts I think? 2. Put a Buick 455 in it, use the engine mount kit available form TA Performance. 3. I would leave your stock springs in and see where it sits and then decide if you need to change them. 4. A/C should be able to be retained, but you may have to scrounge up new brackets or make custom ones. 5. Best performance mods are to add better breathing and better exhaust. That means 4 barrel carb and headers with free flowing mufflers. You can consider a cam upgrade after you improve the breathing. My guess is that you have the 200R4 trans, which should be rebuilt at this time with respect to the much higher torque you will be adding to the car. If you have a 3-speed auto, then you need to junk that non-OD 200 trans and put in a turbo 350, it is very close to the same length, so you can use your existing driveshaft, you do have to adjust the crossmember location. There are several people on the board here that have 455 Regals, so they can probably add better info.
a buddy of mine swapped out a 307 for a 72 buick 455 in his 86 regal. he used the frame pads from the electra the motor came from, but he had to cut them down a little. he then welded them on the frame. he left the stock springs in and they have a decent ride height even though one is broken. he does need new bushings, however, that may determine the true ride height. he runs a rebuilt 200-4r tranny with a lockup converter with a shift kit and a gn type of servo. he has a stock 2.41 posi 7.5 inch in the rear. he's put over 3000 miles on this car with no problems. he drove to bowling green this year and averaged 23 mpg. he ran the car at the track a couple of weeks ago and got a 14.6. not bad for an all iron stock cammed motor with 85,000 miles. btw...i have an olds 455 that no one wants to buy from me. i think its a 73.
455 in mid 80s LeSabre While the Olds small block 400 is a direct replacement, the Buick 455 should slide easy into a "B" body. The difficult part is changing the motor mounts. You are in luck as the car should have an "Corporate 8.5 differential" so you will not have to worry about the wimpy 7.5 units found in typical "G" bodies. It could have a TH 200C that should be replaced as mentioned before. If your are blessed with a TH 200 R4 have it built to handle the 455 as it has the overdrive that will help your mileage for crusing. For accessories and wiring find a mid 80s "B" body car with the Buick V-6 at a salvage yard. Harvest the entire engine wiring harness complete to the C-100 connector that plugs under the brake booster. You will need to unscrew a fastener that holds the two-part connector to the socket. One side will be the chassis wiring harness (that you should not need) and the other is the engine wiring harness. This will make things easier since the starter is on the opposite side and distributor is in front of the Buick while the Olds is near the firewall. You will not need the part of the harness from the passenger side of the car which has all the computer sensor and control wiring since you will probably not be using computer control. From the V-6 car strip all the brackets for: AC, alternator, power steering pump and anything else off the V-6 to mount the accessories from your car onto the Buick 455. Might want to grab the AC, and power steering lines since they may be mounted in a different location taking different length lines. Hopefully you will not need the AIR pump on the 455. This should make a fantastic project, and be fun to drive
455 engines i prefer buick engines but a old will be easier because most of you olds parts will fit. if you new a 455 for rebuilding a have an olds 455 ,apart looks like a forged crank was told a 69 w30 eng with headers and edlebrock intake but have j heads originals gone near chicago if interested :af:
