Which 'modern' car frame will interchange with a 1951 chevrolet four door?

[Guest 1917Maxwell1Ton]

I recently acquired a pretty decent 51 Chevy Styleline DeLuxe with a locked up six cylinder and a 3 speed manual on the column. I am wanting to build something that's not quite a rat rod, but not a restoration either. I would like to have better suspension, the ability to safely lower it, maybe about 2 inches, add disk brakes, a better rear end, a better transmission, etc etc. I am thinking of using an inline six cylinder from a 70's-80's Camaro/truck/passenger car for reliability and low cost of parts. For the transmission I would like to use a TH350. I figure it's a good choice and they are quite plentiful as well and in conjunction with the inline six, it should get fairly decent mileage as well, depending on how the rear end is geared. Same goes with the brakes...simplicity, cost and ease of future upgrades.

So here's my question, is there a 'modern' car/truck frame that will interchange with my car? By modern, I mean something from the 60's, 70's, 80's or 90's. Something with disk brakes, a modern steering column, better suspension, non-enclosed driveline, better rear end, etc etc.

My '51 is a 4-door and from a google search seems to be a 115" wheelbase. Is there anything that is even close to mounting to the body on without a ton of modifications? I know nothing will bolt directly in and "off ya go", I am prepared for a bit of work, but if there is just nothing out there, then I will take another approach such as interchanging the drum brakes for disk, if I can find a suitable spindle that will bolt up and add a dual chamber master cylinder with a proportioning valve for proper brake bias.

If anyone can shed a little light on this, please let me know what would be the best candidate. I'm not good at welding so I would rather not try and attempt something like lopping off the front end and replacing it with a 70-81 Camaro although it seems to be the most popular of choices for this type of upgrade. Thanks in advance for any help!

Here's the car:

Lastly, the picture of the engine below...is it supposed to be so close to the firewall? I don't think that there is an inch between the firewall and the back of the engine. Once again, thank you for any help.

Edited January 25, 2010 by 1917Maxwell1Ton (see edit history)

[joe_padavano]

Nothing will "interchange, BUT start with your wheelbase of 115" and see what matches with about 1" either way. Nothing modern has frames, except trucks. The other option is to use a subframe from a donor, such as a Camaro. I believe a long S-10 is a few inches too long, but shortening a frame is not a difficult or expensive task. Do a google search on S-10 and you will get some of the answers you are looking for.

This is a tough call. Any newer frame will be different and will require much fabrication. The early 50s Chevies are well supported in the aftermarket for spindle, steering, and brake upgrades. These may be much easier to install on your stock frame.

[Rusty_OToole]

Do you mean what modern frame will bolt in with minimum difficulty and expense? The answer is none of them.

Do you mean what modern frame can be adapted given unlimited time, unlimited money and the skills of a team of master craftsmen? In that case, anything you like.

You should bear in mind that cars have not had frames since the eighties or early 90s at the latest, and those frames are very different from 1951 in many cases the frames are wider than your body.

Light trucks like Toyota, Nissan, Chev S15 and Ford Ranger have frames. Some people have managed to hack them into old cars. You have to chop holes in the floor to let the frame stick up through in the back and you end up with a pretty high riding car. But people have done it.

Since you only paid $25 for the car, anything you do will not reduce the value noticeably but it won't increase it either. Whatever time and money you spend, be prepared to write it off as entertainment.

[Rusty_OToole]

If you decide to keep your frame and install new engine, transmission etc you should know that your car has a torque tube drive train and an unusual spring setup at the back.

This means you have to gut it like a trout and replace everything but the ash trays. Engine, trans, driveshaft, rear axle and rear suspension all have to go.

Ifyou wish to avoid this, it is possible to bolt a later Chev V8 or six to the torque tube type transmission given the correct parts (which may not be easy to find these days). If you do that use a six or a 305 and go easy on the gas pedal, the original drive train was barely strong enough for the old 90HP engine.

If you want to fix 'er up on the cheap, any Chev six up to 1962 will bolt in. From 1954 to 62 they have modern insert bearings and full pressure oiling and make it possible to drive in modern traffic without blowing the engine.

To use a newer engine you need the correct transmission. There are 2, one of them will bolt up to any 1955 or newer manual trans bellhousing the other will not. The one you need was made from 1941 to 1954 and was often found in pickup trucks although they were used in cars too. With this tranny you can bolt on the newer bellhousing and bolt on any Chev V8 1955 up or Chev six 1963 up.

[Guest 1917Maxwell1Ton]

Rusty O Toole, you gave the information that I really needed to hear. I want to do something basic. I want to upgrade the brakes at the very least to a dual reservoir master cylinder and disk brakes. I have heard that there are certain 'newer', ie: 70's model cars, brakes that will work on the existing spindles. I am prepared to get an adjustable proportioning valve since each 'newer' car has a proportioning valve suited just for the specific car that it's on.

As for the engine, No one around here has any of the older sixes that you mentioned. I did however find a 6 cylinder from a 78 Chevy truck with a 3-speed on the tree. I am not concerned about raising the value of the car, I just want it to be a fun occasional cruiser that is easy and safe to drive.

Also, I have heard that a 94 model truck steering column will bolt up fairly easily to the existing box with a simple swapping of the rag joint and column supports both inside and out. Is this true?

I have seen the underside of the car and the driveline setup. It looks difficult to modify, but I am up for a challenge. I would like an open driveline with a stronger driveshaft, preferably from a car with an open driveline that can handle the power of about 200hp because I do eventually plan on lightly modifying the 6 cylinder that I install. I really would like to install either a Powerglide or a TH350 trans into the car and like I mentioned, I am up for the challenge...as long as it does not present a mountain of modifications, fabrications and a ton of welding as I do not know how to weld at all, but do have some friends that can.

As for the differential, is there an existing 60's to 90's differential that could work? I know I would have to cut all mounts off of the new rear end as well as the old and put the old mounts and such on the new rear, even with a newer driveshaft and such. Now the springs. Is there any spring that is compatible with the springs on the front as well as the back that would give me a nicer ride and still allow me to eventually lower the car by 1-2 inches or am I stuck with what is there?

Back to the engine. Could I cut off the existing mounts for the engine (and trans) and weld on newer engine mounts for it as well as adapt a 'modern' crossmember for the transmission, thus allowing me to have an open driveline? It seems like the open driveline would not present itself as a majorly difficult problem if done this way if I decide to keep the existing original frame. Just modify things here and there.

Sorry for the ton of questions, I thank you for your help, you have been very informative!

[joe_padavano]

If you decide to keep your frame and install new engine, transmission etc you should know that your car has a torque tube drive train and an unusual spring setup at the back.

This means you have to gut it like a trout and replace everything but the ash trays. Engine, trans, driveshaft, rear axle and rear suspension all have to go.

This problem has been solved for decades. There are LOTS of early Chevies on the road that have had the torque tube removed and it did NOT require a rocket scientist to make it happen. Swapping out the rear axle is not that difficult. Once that is done and the new engine and trans are in place, measure for the driveshaft and have one built to the correct length.

Note to the original poster: This is not the right forum for your question, since this site is dedicated to totally stock restorations. Try the H.A.M.B. for what you want. Many, many early 50s Chevies have been built with later model drivetrains. As I noted, these cars are WELL supported in the aftermarket for exactly this sort of thing. If you want to keep the I6, a later model 250 or 292 can be installed with little trouble. The DOHC Vortec 4.2 liter I6 from the Trailblazer would be very cool, but would require much work and cash. Small block Chevy swaps into these cars are as common as bellybuttons. Your money, your call.

[Rusty_OToole]

You will have to measure the width of the rear axle then start shopping the junkyards. I have heard the old Novas have the right width of axle, also a Chev S10 or S15 pickup is close but not exact.

In any case you will have to cut the spring mounts off the axle and weld new ones on because they are in a different place. Also the original mounts are offset so you have to drill a new centering hole in the mount, to get the wheel correctly centered in the wheel well.

The front spring mount has to be changed, in fact most guys replace both the front and rear spring mounts and the springs as well.

I have not done this swap but as Joe points out, many others have. His suggestion to check out a hot rod bulletin board is a good one. Do a search first, no doubt your questions have been answered a million times.

It is also possible that someone makes ready made motor mounts, axle mounts etc. I'm sure you can buy a disc brake swap kit.

The steering box will not fit, they are a totally different setup. I hope I am wrong on this, go back to the guy who told you it would fit and ask him. But I don't see how it could work.

In most of these projects the welding is the least of your worries. Figure on about 1 hour of welding for every 100 hours of fabricating metal, wiring, making linkages, plumbing, etc.

For welding you can make up the parts and take them to a shop or to one of your buddies. That's what I used to do when I did not have my own welder.

[joe_padavano]

In most of these projects the welding is the least of your worries. Figure on about 1 hour of welding for every 100 hours of fabricating metal, wiring, making linkages, plumbing, etc.

But THAT'S the fun part...

Seriously, I think that statement is a little pessimistic, however good planning (measure twice, cut once) is always a smart thing to do. Rod and Custom recently had an article about the rear axle swap into an early 50s Chevy.

[Guest]

I had a friend (passed away) that had a 49 Olds 88 that he put over a mid 80's Cutlass G body chassis and told me it wasn's too difficult. The body shell of the Pontiac/Olds/ Chevy is the same but the frame and front fenders of a 49 Olds 88 and Pontiac are longer. In fact the Pontiac has 120" wheelbase and the small Olds (76&88) is 119". The chevy at 115. So the length is from the firewall forward. I'm sure you could section a G body frame because they are built on a 108.1 wheelbase.

I am curious though and no offence to you or anyone, why on a AACA forum whould you ask that question??

Don

[Guest 50Chev]

I did it with a 1950 Chevy 2 door on a 1983 Caddy. DON'T DO IT! Go the subframe route, and transplant the modern rear end.

[Sweepspear]

I think you should ask this over on the H.A.M.B. board, if you haven't already.

There will be more people experienced in this sort of thing there than here.

[MCHinson]

Guys, you are responding to a 3 year old discussion. Hopefully he has already done whatever he was going to do.

[Sweepspear]

Oops!

How is it newbies dig up these old threads on every board?

[MCHinson]

Sweepspear,

Normally they find them through a Google search...

50Chev,

Welcome to the AACA Discussion Forum. Hopefully you will find some more recent posts that interest you as well.