I have a 38 Buick Coupe that is 100% original. I have a healthy 401 Nailhead and a switch pitch 400 that will be going in it. Id like to update the front suspension with modern tubular arms and ball joints instead of king pins. I'm not interested in MII stuff or grafting a late model front clip. I'm a decent welder and fabricator. Any suggestions ?
If it were me…keep the straight axle and replace the kingpins. Really isn’t much wrong with stock front ends.
Better shocks would be good. Bilsteins have been recommended. What makes you unhappy ride control wise One thing to remember is that those years cars had to run on less uniform roads. Many had curves to follow the creek, and raised railroad crossings.
I once did a late 30's Mopar and used Ford ranger upper/lower control arms and spindles. Don't know how it drove out as a little while later after I got it all installed the owner got an offer he couldn't refuse for it and sold it. Never heard or seen anything else to do about that car. But I used the original control arm mounts (top & bottom) off of the donor frame and welded them to the original Mopar frame. Actually worked out pretty slick..... ...
Now why would ANYONE with a lick of sense replace , ESPECIALLY in a BUICK, the coils with an archaic straight axle?? Ben
I like straight axles. However for the Buick I would rebuild whats there with some new shocks, done deal
It's all been rebuilt including the lever action shocks. Zero miles on it. I guess I'm just concerned about more than tripling the horsepower and torque on 1938 technology
If it was my decision, I would go for a Jaguar front end and steering. (I already apologize to the traditionalist, but the Jag front ends tend to cost about $250 down here, and the ride is great) I had one in a 48 Chev pickup, and it was the best riding hot rod I ever had. And now Im too old to fight a beam axle.
TBH, I understand the rationale behind going MII if you're starting with a car that has a straight axle. The IFS is a substantial improvement in handling in that scenario. However, in your car with a car that already has IFS, a properly functioning factory system is really all you need. You can retrofit a later model steering gear in, like a 72 Nova, and convert the drums to power disc, which will give you a better, cleaner end result with less overall work. A win/win. Grafting the suspension from a donor vehicle IMHO is a sloppy means of achieving what you're doing, and rarely turns out well since the track width is typically wrong. At least an aftermarket MII stub will have the proper track width. But I can tell you from experience that my 56 Olds with good kingpins and a 72 Nova steering gear, steers great and rides like a dream. I don't see a benefit of removing a system like that
It might not be all that dificult to fit a ball joint to the lower control arm (s) These shots snagged from Ebay. The uppers will take a bit of creative fabricating. Spindles will have to be rear steer spindles. That will limit things a bit if you want a disk brake spindle.
I've got a jag crossmember that might go under my 48 now but on that particular Buick it calls for too much frame modification to work as the spring buckets are built into the frame. the frame is pretty wide and has way too much stuff that would have to be cut off to make a Jag or any other front end swap work.
A friend retained the OEM IFS in his 47 Oldsmobile and adapted later disc brakes to the spindles but had to fabricate caliper brackets and a dual MC mount. He swapped in a matching bolt pattern rear axle, rebuilt the kingpins etc and drained the shocks, albeit some residue for lubrication, and added telescopic shocks. He used a Daewoo Lanos R&P similar to Cadillac Cimarron. Is the Buick open or closed drive-line?
Most likely, the front end is not the weak spot when thinking of increased hp and torque. Change out the steering and brakes and get it on the road and drive it for a bit before breaking out the cutting tools and welder.
Because of the frame design, the options are limited, unless you want to cut the frame. There is an article floating about on crankshaft coalition detailing a procedure to convert to a ball joint suspension. 1958 Pontiac lower control arms are a bolt-in and have ball joints, but good luck finding them. 1958 Olds or Buick uppers can be used, but the Olds have built in anti-dive twist. A piece of angle iron mounts the uppers. This set-up requires 64 Chevy Impala spindles, which are available in a dropped version from CPP. I considered this route on my 40's, but due to not finding the lowers, went with dropped uprights (available from Downright Fab) and disc brakes from Scarebird. The 401 (which is going in one of mine) is lighter than the I-8.
The stock front end rides and handles surprisingly well and is plenty robust to handle the Nail Head. The only drawback is you can only get about 1 degree of positive caster, but for a cruiser will be fine. The new Scarebird has the correct kit to upgrade to disc brakes on the OEM spindles, as well as an adapter to mount a Wildwood remote reservoir MC.
Correct, like I previously mentioned, my 56 Olds 98 has factory kingpins, albeit with a tube shock as opposed to the lever action. It handles and rides better than virtually any other "old car" I've had, including a 57 Ford and 57 Chevy, both of which came with ball joints. I think the concerns surrounding the horsepower increase are unfounded. If your intention is to build a car that carves up an autocross or can make sudden handing maneuvers at very high speeds, then absolutely, by all means call Roadster Shop for a new chassis with Corvette spindles and brakes, and LS swap it, and you'll be good. On the other hand, if your purpose is to have a nice driving/riding, reliable old car to cruise around in that is safe at speeds up to around 80 mph on the highway, then the factory setup will be perfectly sufficient. Moreso than the suspension itself, it will be important that your brakes and steering are up to snuff. A disc brake conversion requires no alteration to the design of your suspension and ill give you ample stopping power at higher speeds. An improved steering gear will allow your steering to be more precise.
Thanks for the suggestions. I think I'll initially improve the steering and the brakes and see how it drives from there.
How do you plan to shift the tranny, floor or column? If column, a unit out of a mid 60s Chevy C10 mated to a Borgeson box would improve the steering. That column matches the detents on the TH400. The Scarebird disc brake kit uses bearing adapters to convert to roller bearings and uses Rivi rotors and Chevy Astro calipers. Those rotors keep the 5 on 5 BC.
If the front end is in great shape now I'd just drive it and decide then. You have to remember that back in their day those straight 8 bucks were the "affordable" fast road car that you racked up fast miles with on far worse roads than we have today. Strength isn't an issue and I'd bet that strenght wise that stock front end will be stronger than any tube A frame setup you make for it. The nailhead is probably a bit lighter than the Straight eight that runs 750 to 800 lbs. The 292 Chevy six I have for my 48 is Heavy for a Chevy engine and runs about 560 lbs The 401 nailhead is said to weigh 625 or so so you are loosing 125 to 175 lbs off the front end right there. Generally on one line that the main reason to go to later model or Tube Arms with ball joints is that it just flat costs too much totally rebuild all the pieces in the stock suspension. 545 to have Apple hydraulics rebuild both front shocks is just part of the cost. Then you get in the rare parts catalog for a lot of the rest but if if it isn't broke I wouldn't be in a hurry to fix it.
Keep in mind that the lever action shocks need to stay in the general operating range as stock. Not only is the 401 lighter than the I-8, the centerline of the engine weight shifts rearward some. In addition, the radiator will likely be aluminum (Wizard Cooling is the only one that makes one that I know of), reducing the front end weight even more. If the stock stuff is intact, a quick measurement from the frame to the floor will let you know where you need to be at the end. Adding accessories such as A/C can change things. The original front suspension was engineered for the roads at the time. A lot of rural roads were no more than rugged dirt roads, so the suspension is plenty robust.
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