1975 Buick Apollo 400 swap

Discussion in 'The "X" bodies' started by ApolloX75, Oct 7, 2013.

  1. ApolloX75

    ApolloX75 Member

    This could be a long thread so have patience.

    I started with this 75 Apollo sedan in '03 when my dad found it in a junkyard. Didn't even know what it was but fell in love at first sight. We towed it out and hosed off the 30 years of grease and road dirt to reveal a solid, if somewhat neglected, chassis and a rusty body powered by the original experimental 260 Olds mated to a th350 with only 60k on the clock. Power discs, power steering, no a/c, vinyl bench, white on red, 2.56 open different on rusty steels.
    I stopped and started work on this car about a dozen times, it was a lot for me to take on with limited space and still in high school but eventually I got started and removed one piece... And then another... And another. Eventually I just kept going til I had removed the whole front frame and sent it out for sandblasting and paint. I ordered heavy duty springs and replaced every suspension piece with new, improved parts. At the same time I decided to fulfill an old joke I made with my dad about shoving a pontiac 400 that he used to race with in place of the 260. We went through his parts and found everything from block to intake, had it tanked, machined and blueprinted and built it over the winter.
    Now I know some people will be disappointed at my using a poncho mill and I understand that. However keep in mind I live in Canada and things like a nice buick 455 are extremely rare and even harder to find aftermarket parts for than a pontiac.
    Dropping the 400 in was not easy it took a crane and two friends help to do it over two days. I had to tack the clamshell mounts on the frame and lower the engine down to see how it fit repeatedly and then weld and bolt the mounts in place. The engine sits so low that it is physically impossible to remove the oil pan without lifting it out. However everything lines up perfectly straight and a regular air cleaner fits under the stock hood.
    I have a solid 8" between a clutch fan and the rad, plus enough clearance to keep the stock steering setup. Exhaust was easy with a set of good manifolds and 3" pypes downpipes modified into a true dual setup.
    Unfortunately I built the mill a little too well and even with the wimpy 2.56 rear end it demolished the th350 so it is back in the garage while I get set to do Muncie swap. Still need pedals and a proper z-bar setup then I'll be set to install it and my auburn 3.08 posi.
    I'll post some pics tonight when I get home.
  2. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    I look forward to the pics, the 400 Poncho is a VERY well designed engine!
  3. newmexguy

    newmexguy Well-Known Member

    Still need pedals and a proper z-bar setup then I'll be set to install it and my auburn 3.08 posi.
    I'll post some pics tonight when I get home.[/QUOTE]

    proper z bar setup? was there ever a pontiac engine (350) in a 75 - 79 X with a manual shift? now that would be a rare bird. I have seen a few Chevy manual stick setups in the El Paso yards, pretty much have sold every one i have found.
    think you may need to go hydraulic. yes i would like to see some pics.
  4. ApolloX75

    ApolloX75 Member

    Some pics for everyone. Unfortunately I lost a lot of my originals so until I find my backups these will have to do.
    260 slug.jpg Original side.jpg First pic.jpg These are from the day I brought her home, that was a loooong time ago.

    Body Panels off.jpg Frame rebuilt.jpg Before and after removal of the sub-frame. It was a lot of work but damn was it worth it.
    400 almost complete.jpg 400 Crank and pistons.jpg 400 crank installed.jpg The 400 bored .060 over. Blueprinted and pre-built in my basement, then finished in the garage a week before we put it in. Clevite 77 flat-tops, forged rods, ARP studs, reconditioned 6X heads with over-sized valves, the works.

    Engine seated.jpg Fully mounted and snug.jpg Mounts.jpg Took two days with an engine crane and some burly friends to muscle it in place as well as hold everything in place while I marked and tacked the mounts in place, then drilled the frame. Even worse was getting my hands in to fasten the locknuts on the inside. The pan sits about an inch off the crossmember so in order to replace my blasted rope-main seal I have to lift the engine out again.

    Driver clearance.jpg Some assembly required.jpg Tunnel clearance.jpg Wheels up, steering in.jpg There is lots of clearance around the engine allowing me to use almost everything original including steering. It's a tight fit between the rear and the firewall but I work around it. It didn't take long after all this to put it all together, the worst was putting in the bellhousing bolts. I don't have pictures of the exhaust, but it is roomy and pretty straightforward. A set of Pypes Pontiac downpipes sealed the deal and solved all my issues. A muffler shop welded a full dual setup tucked up nice and tight straight back and over the axle.

    400 running before TH350 blew up.jpg And that's it. That was it running last year after I put in the new overflow canister. About two weeks after that the TH350 gave up the ghost so it's been limping ever since as I get parts together for my Muncie swap.

    I'll post more pics when I get a chance to dig up my backups and take some new shots as I perform the swap. Also leather buckets going in this winter too.
  5. ApolloX75

    ApolloX75 Member

    I have to agree it is very difficult to find parts. I have the hydraulic setup from an 88 Firebird that I think will work but I need a clutch pedal set and then I can monkey it all together. I am going to try and mock up the pedals I took out of the 'Bird but I don't think they'll work properly.
    I saw there was a guy on here talking about making his own pedals, and I work in an aluminum shop so it would be easy enough to make them but I don't have any dimensions or information on the curvature and the like.

    I'll think of something I'm sure. :p
  6. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    For the pedals you should be able to expand your search in the 73-75 Ventura, Nova etc as they should be the same or VERY close. Being that you are going Hydro, just find some pedals that fit in there well and then modify them to work well with the hydro... It is not like you need to keep the factory geometry like you would if you were using the Z bar etc.
  7. newmexguy

    newmexguy Well-Known Member

    I may? have one small brake pedal from a 75-79 manual shift Nova left, it needs some work to one of the brake pedal push rod holes (hogged out)
    pay shipping and its yours. Am going to guess 73-74 pedals are closer to (68) - 69 - 72 's.
  8. ApolloX75

    ApolloX75 Member

    Sweet, PM sent. Thanks! :D
  9. ApolloX75

    ApolloX75 Member

    Wow. It's been years since I've been on here and I hate to zombie an old thread but this is a relevant update.

    It's done.

    After almost six years and two more dead automatics (a 2004-R and a TH400) the Muncie M20 swap is complete. The pedals I was so worried about? Not even an issue. We just built our own mechanical linkage out of spare parts and set up our own geometry; we used the clutch pedal from a second gen F-Body and a brake pedal from a third gen F-Body with some minor modifications to both, no clearance or fit issues whatsoever and perfect spacing. We used a wide ratio 1970 coarse spline Muncie M20 out of a Corvette with a Hurst competition shifter setup and it works great, no fussy business. So now with my drivetrain complete; which includes our successful 3.08 gear set and Auburn posi install this past summer, I can finally relax and focus on all the body issues over the next year or so while I enjoy driving my beast. I'll post some pics of the pedals and linkage setup but for now here's an Apollo on a hoist.

    docgsx likes this.
  10. ApolloX75

    ApolloX75 Member

    As promised here are some more pictures, maybe some day these will help someone who is trying to do a similar swap. Who knows. We ended up making our own bushings for the pedals and used a 7/16 bolt of sufficient length to make everything right. We ground off the old stud on the brake pedal and milled a 3/8 hole at the right spot to bolt the booster push rod so it lined up nice and straight like the OE pedal, and extended the original tab to help it make contact with the brake light switch. The clutch pedal was even easier as we simply hung it and used it as is with a snow blower actuator rod cut and bent to the right shape and length to reach the Z-bar lever. Use what you got, right?

    We needed a shifter handle of sufficient length as well and ended up cutting down a Hurst auto stick to about 9" length and milled some 3/8 holes in the bottom of the rod to line up with the bolt holes in the Hurst competition shifter on the Muncie, ended up being the perfect angle and is nice and comfortable to use.

    Now all that's left is to clean up the wiring that's been added in and finish the body, so more on that as I go this year.

    IMG_20190129_162558_01_01.jpg IMG_20190131_162847.jpg IMG_20190131_185904.jpg

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