Lonnie Cobb - '55 Chevy Straight Axle Project

As many of you know Lonnie is putting together a 1955 Chevy straight axle car. I thought it would be fun to document the project right here on our website. I'm especially excited as I'm following in his footsteps with a '56 Chevy straight axle car next spring and summer.

I will try to post as many details on the build as I can and please let me know if there is anything you want to know and I will try to find out the answer to your question.

On with the Project!

Here is the '56 Chevy one piece frame that will be used for the project. It has the front suspension cut off just forward of the steering box holes. This location of cutting off the front suspension was taken from an April 1967 Hot Rod magazine article. The frame has been coated with Por15 also.

Here is a picture of the frame with the 3:70 equipped Ford 9" rear that Lonnie got from a Divco milk truck installed. The rear springs are 55-57 5-leafs with Mr. Gasket shackles and new bushings. The spring perch's have been relocated also.

Here is a picture with the free ET slots mounted on 275x15 Goodyear Eagle II's

The front axle is a '49-'54 Chevy truck axle and the re-arched front springs. The axle has been drilled with eleven 3/4" holes and will be painted black. The '49-54 truck axle was used because with the spindles mounted it is almost the exact width of the stock suspension of the '55 Chevy.

Here is the frame at Bob Crawford's house with the 2x4 steel welded in.

Close up of the location of were you cut off the front end and the 2x4 steel frame.

Welds cleaned up a bit.

Here is the front axle drilled and painted. Again this is an axle from a '49-'54 Chevy truck and was used because it will place the wheels at almost the exact same width as the stock front end. The spindles are '49-'54 chevy car spindles. Car spindles were used because the disk brake adapter kits are more readily available for car spindles.

A disk brake adapter kit is pictured with the axle. The kit was purchased from ECI. With this adapter kit you can use rotors and calipers from mid 70's GM cars. Also pictured on the lower left are front leafs spring perches with shackles. Larger perches to the right are for rear of leaf springs, no shackles are used on the rear.

Here is Bob (on the right) and Ray checking out the workmanship. Bob does metal fabrication and paint/body work as RTC Enterprises. Bob has many years of fabrication experience and has partnered with others in the Rebel Rods car club to build hot rods together and is one of the founding members of the Rebel Rods Car Club. You can contact Bob through e-mail if you are interested in any fabrication work you might need.

Here is the frame with the axle and springs in place. The springs were setup to handle a big block and may have a few leafs removed after the motor and body are on. A chrome moly tube was used as a front crossmember.

Here is the Saginaw 525 steering box installed. It was used over a Vega box because of the weight of the vehicle and they are common and available and still not too large.

Here is a shot of the mounting bracket for the front of the spring. The reason for re-arching the springs is to minimize shackle length mostly for appearance, also for stability. It just plain looks cooler!
Note: Leaf springs were originally flat.

Here is the rear mounting bracket of the spring. The mounting position of the spring perches is determined by the location of the axle after it is centered.

Here is the '55 with the motor mounted. This small block should pump out over 400hp! Motor is mounted very close original location front to back, but was raised up 2"-3". A Saginaw 4-spd is used for now.

Front shot of the chassis with the motor in place.

Passenger side motor mount. These were purchased through Speedway.

Here is the drivers side motor mount that was notched out for the steering shaft.

Here is the fabricated transmission crossmember. L-brackets were welded to the frame to mount crossmember.

Part of the crew drinking beer and checking out the workmanship!

The new chrome shocks mounted.

The tilt fiberglass frontend.

Here is the '55 Chevy body that will be used.

Here is a shot of the frontend hardware. Tierod and draglink is from Speedway and the steering arms are from a '55 Chevy.

Front shot of the suspension.

Here is the chassis with the body on, ready to go to Bob's house for the body work to start.

Another shot of the frontend.

Here is the car with the fiberglass front end on the car. This will probably not be used and steel fenders and hood will replace it, but doesn't it look badass!

Passenger side. The rear wheelwells will be radiused out at Bob's house.

Check out that mile high stance!

Rear shot!

Floors all roughed in.

Patch panels tacked in and the rear wheelwells radiused

Here is the dash painted a metallic green, this thing pops in the sunlight!

Steel front fenders and hood in place.

Cool front end shot!

Getting ready to trailer it back to the garage to start getting it road worthy.

Here is the '55 with the new front wheels on and the small block and glass in.

Healthy Small Block!

The 400+ hp dual quad 409!!!!

Coolin' Down at Goodguys in Iowa!

For those that might want to build a straight axle car there are 2 things that are very important to keep in mind if you want to have a decent handling straight axle car. First, you need to make sure that the draglink is parallel to the top of the axle as in the picture below. This means as you are looking at it from the front of the car. It doesn't necessarily have to be parallel front to back, but should be parallel woth the top of the axle.

Second, caster is by far one of the most import things to get correct if you want your straight axle car to handle correctly. If you use a factory type straight axle setup the caster can be adjusted by adding a wedge shaped shim between the axles and springs. You want to have at least 10 degres of positive caster, which means the the axle will be tilted backwards 10 degrees..

Check back soon for more pictures and details