[EDNY]

Trying to understand measurements related to complete chassis swaps. As an example if I decide to rod my 37 Buick coupe I would prefer to just swap an entire rolling chassis.

The 37 Buick coupe"

Wheelbase 126"
Front track 58.31"
Rear track  59.25

2004-12 Chevy Colorado ext. cab two wheel drive

Wheelbase 126"
Front track 57.48"
Rear track  57.48

When really lowering the 30's cars doesn't that affect the wheelbase measurement some?

Would the OEM Colorado wheelbase also have the same wheelbase effect if also lowered? (rear leafs front torsion)

(Seems that of the "30's" cars that I lowered wound up moving the rear axle about an inch rearward to center on the rear fenders?) 

[sammons]

Ed, I don't see how lowering would change the wheel base any, unless you put one heck of a rake on one.   I asked dad one time as a kid if an old car had  been hit in the rear and bent/shoved the frame forward. He smiled and said no. If you look at most stock 30s-50s cars, you will see that there are a lot (stock) that mainly the rear sets forward in the wheel well. When lowered it really looks even more forward. Most guys modifying suspensions or fabbing new chassis set mock up wheels  centered in fenders at ride height.

Just what I have noticed since I was a kid

Here are some stock car/p.u. side views.

[39delux]

Never been a fan of using a (modern) frame to slide under an old car.  Wheelbase is wrong, width is wrong and contour is wrong.  Outside of that they fit like a glove!  Several different ways to go with updating the frame.  First is to use the existing frame and stiffen with a K member, boxing and maybe scabbing in rail stiffeners.  Second is to order a new frame from a street rod builder that specializes in this.  That's expensive.  Third option is to build your own new frame.  With each option of course the suspension will be upgraded.  I opted for #3.  Could not find a good set of measurements for a 1939 Chevy frame so I put the car on a lift and plumb bobbed each section of the rail to the floor and drew out what "birds eye" of each rail should look like.  Set the car on the floor and measured height of each section.  I was then able to draw out a complete frame rail and then on to a complete frame.  I used 2" X 4" 3/16" rectangular material for the rails and smaller stuff for the K member.  Fun project with the steel costing under $200. 

[EDNY]

Thanks guys...sammons those pictures demonstrate what I mean about the rear axle appearing too far forward.

[sammons]

Ed I don't know why they built them offset from the factory. I thought about it for decades. Was there a reason???  The only rear suspension i remember changing W.B. slightly when raising or lowering was on a long trailing arm/ladder bar set ups.

I think the only way to know how close the Colorado swap, would be to have one handy to measure how close profile matched. Knowing the width of both frames, main rail and kick up heights.  Front steer/ rear steer if any difference and floor /trunk pan interfearance problems.

 My buddy Shane makes alot of frame swaps, (usually because he has no frame)  and does them in a couple days. Makes it look easy.  I haven't done a complete late model frame swap.

[EDNY]

sammons

I really need to check out a 2wd Colorado chassis, thought they had the torsion bar suspension up front (easy height adjustment) but now I see pics with standard coils. Something different about the leafs on the back also.

[munch]

Wouldn't it be great if there was a site for late model donor chassis that you could just enter 1930 Chevy Coach and it would pull up compatible donors and any particular about the swap.

[EDNY]

Wouldn't it be great if there was a site for late model donor chassis that you could just enter 1930 Chevy Coach and it would pull up compatible donors and any particular about the swap.

This is the closest we have:

http://www.crankshaftcoalition.com/wiki/Wheelbase,_track_width,_and_differential_measurements

[munch]

That is good information, thanks Ed.

[Kiwijeff]

My Hudson uses an 83 Toyota Ute chassis.
It don't count in this discussion, due to channeling and being built to fit chassis. If your doing a truck, I guess it's easy to mount the rear fenders where ever you need to, so they are centred.

[ghost28]

I ususally try to get in the same decade on different frame swaps except the 20's cars I will try for a 30's frame.  I even used a 32 chevy frame for using all the suspension components from a 92 vette on my 32 chevy once, but always stay with the original frame designs. Just me I guess. I did like the nova and camaro swaps for the fat fendered cars.