Impala Wagon Swap build.
Plenty of people have claimed success with just installing sedan 3rd members in wagons but there are real differences. When I did gears/posi/bearings in mine I was given sedan wheel bearings by mistake and the wagon wheel bearings are MUCH bigger, for example.
Sorry for not reading more closely, I'm just suggesting you verify housing length details etc to make sure you get a suitable replacement.
Thank for this thread and keeping us posted on the progress.
the Bubble rear end "Should" be a direct swap for my Box body. Width and all. The wagon frame is wider, so even springs and such are spaced wider. Though many do the Impala SS swap to get disc brakes, there are some drawbacks to using a sedan rear. It was was my fallback, but luckily i was able to source a wagon rear end from a 96 roadmaster wagon for the car.
Picked up a used 8.5 rear end from a 96 Buick Roadmaster last week. Regeared it with my 4.10's i already had. First time doing gears...here hoping it holds up!.
Installed the new rear end today. Easy swap, took an hour. No pic, as it looks just like the old one.
Then i decided to work on my Exhaust. First steps was i knew my trans crossmember was in the way, It needed some clearance holes.
Then did a bit of piping. Options were limited.
Also had some new meats dropped off for it as well. No budget for wheels right now but tires were needed due to dry rot on the old ones.
Car is MUCH more driveable with the 4.10's as well. may actually be a touch low from my first impressions, but i'll take it over too high anyday.
What size are your rear tires? (How tall?) Looks like you have room for taller and wider rubber back there...Helping those 4:10's be easier to deal with...
I see, that's the same size I run on mine...I honestly think you will love the 4:10's out on the road in high gear.
Anyhow, that thing looks really bitchin' with that tire/wheel combo...
The tires made this wheel work. the 225/70-15's i took off just didn't look right. Not going to be my permanent wheel, but it will certainly do for now. Hopefully Next year putting 18's on it and dropping in just a touch, 1 or 2 inches.
and i am sure the 4.10's will be great, Just made it a bit lower than i expected, but in 6th gear cruising at 75 I should only be running about 1850 RPM which will be nice.
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I guess I kind of "split the difference" & selected the 3.70 gearset. My car's not running right now, but I'm guessing it'll mostly work all right, but I probably won't use 6th that often... (At least it should be relatively easy to change ratios in this rearend if I decide it's necessary...)I suspect that the added mechanical leverage of the 4.10s will work well with the extra weight of the wagon - after driving it for a while, you'll probably never want to go back!
I guess I kind of "split the difference" & selected the 3.70 gearset. My car's not running right now, but I'm guessing it'll mostly work all right, but I probably won't use 6th that often... (At least it should be relatively easy to change ratios in this rearend if I decide it's necessary...)I suspect that the added mechanical leverage of the 4.10s will work well with the extra weight of the wagon - after driving it for a while, you'll probably never want to go back!
That is the same dillema i faced. Too high and 6th becomes useless, too low and you wind out first before you even get rolling. I'll take the lower gear for sure with that choice. The wagon is not as heavy as most people think. have not put it on any scales, but stock it was supposed to be right at 4k which is light by todays standards in cars. I plan on weighing it first chance i get.
Today, drove it around the house a bit. Shifted through a few gears. all seems pretty well. Getting a buddy to tune on it a bit Wednesday to get it closer to right so i can drive it around some. Plan on taking it Home saturday to do some last little tweaks on it before I take it for the Dyno tune Next friday. I am equal amount excited and nervous. Excited to get to drive it, nervous something catastrophic is gonna happen first trip out. The end of a build is the part i hate most. I love actually doing the work, but hate testing it due to my fear i screwed something up.
4.10's are definitely lower than i would prefer based off what driving i did yesterday, but i will get used to them. Seem to be set up decent as i heard no noise from the rear end while tuning. overall, very happy with the first drive. Can't wait to get it tagged next week so i can drive it a bit further without worry.
Drove it home a total of about 20 miles, mix of backroads and a very short 2-3 mile interstate run. Drove nice, all gears felt decent, though you have to shift into 4th gear with purpose or else it will grind so i think a trans overhaul is in my future.
on the way however, the brakes started dragging. the more i dove it, the worse it got to the point i had to pull over and let them cool off. Popped the bleeders to release some pressure and drove it on home the last 4 miles or so without issue.
There is something screwy with the brakes, as there is no soft spot in the pedal. with the engine off, the pedal is rock solid from the get go, no slack what so ever in it before you get brake action. Engine running, not much slack at all before it gets firm. Brakes work well, but i think something is up with the booster or MC, possibly the pushrod length though it should not have been affected by the pedal work i did.
Spent a few hours on the dyno. Went to ShorTuning in Danville, KY. He uses a Dyno Dynamics dyno, operates similar to a Mustang and is a load bearing type so was able to tune driveability on the dyno as well. Numbers were less than i had hoped for, but read that these are real heartbreaker dynos. Final Numbers were 323HP/336TQ. Really thought it would be more considering my mods. Oh well, car is still a blast to drive and runs really well.
Full specs on the engine are 2005 LQ4, 862 Heads to bump compression up to 10.5:1, 220/228 .600/.600 109+4 cam. F-body Headers. Otherwise all stock truck engine. The intake and heads both are not know for power up top, but help down low. I too expected more.
Using my Brothers L77 in his caprice as a baseline, he put down 340 on the same dyno cam only. granted, better heads and intake from the factory, but i have more Compression and full exhaust so i figured my numbers would be closer to his despite his better flowing top end. But really comparing apples to oranges as the type of build.
in the end, i have put 1500 miles or so on it since then and am very happy with it. always want more power, but it is plenty fun at the current level...for now. Eventually might go with a TBSS intake, some milled 243/799 heads to get more flow but keep my compression. Maybe eventually add a blower, but that is all a bit down the road.
On that note. Driven the car almost daily since having it tuned and tagged. Drove it on one leg of the power tour from Sparta to Indy and back home, for nearly a 400 mile round trip in one day. Very happy with driveability of the car. it was a big unknown, i knew the PO had driven it on a trip not long before I bought it but i had never driven the car myself. Cruised down the highway at 80, straight as can be. no pulls or anything. Steering is Very light, so i want to tighten it up somehow to get more feedback from it. it is currently 1 finger power steering. Only issue thus far is my E-fan stopped working on me. New, 2 speed derale replacement is on its way. But even without the fan it only gets a little warm in traffic, as long as there is no traffic the car stays at 200-205 running temp.
Still lots to do, but after summer is over and i can enjoy it for now.
Last edited by underpowered; Jun 19, 2019 at 07:49 AM.







