Our new Big-Block (and small block) Generation IV direct replacement, mandrel-bent, jig-built, street performance Chassis is now available for 1955-57 Chevys with many options available for tri-five Chevys! This is the fourth version of our tri-five chassis since we started building them in 1993! This is also the strongest version! Of course it will handle mouse motors, but we designed and built this chassis to handle lots of big-block power and torque! It utilizes all stock body-mounts, inner-fender panels, stock core-support, and bumper bracket mounts, all in their stock locations! We offer the chassis in either right-or-left hand drive for convertible, hardtop, or sedan bodies. All of our new G-4 chassis now have the larger 2X4 box tube X-member that gives extra strength for the delicate convertible bodies and will take all the torque you can fit under the hood. You will see in the following photos that the new larger 2X4 box tube X-member connects directly to the rear 4-link crossmember to put all the power to the ground.
The standard chassis package features 2 X 4 X .120-inch wall box tube CNC mandrel-bent chassis. It has an additional 1-inch step over the front suspension and a 1 1/2-inch additional step over the rear suspension. To accommodate the lower chassis, the engine mounts have been raised for increased ground clearance for headers and oil pan. Either big block or small block engines can be used with the stock rear-sump oil pan. The engine mounts have been moved forward slightly to install the larger distributor cap of the popular HEI GM ignition without cutting into the stock firewall.
The stock 115-inch wheelbase G-4 chassis features our new 2X4 box-tube X-member, a vast improvement over the stock chassis that has only two crossmembers! Instead of side-chassis motor mounts, we've designed new 1 1/4-inch X .120-inch wall D.O.M. support tubes that connect between the inner frame-rail sides and the front crossmember that hold stock GM motor mounts. This gives additional support to the front crossmember and the chassis rails for plenty of big block power. Notice, our new transmission crossmember has also been designed to be more exhaust friendly, and each transmission side-bracket features all the holes for the most popular GM and aftermarket transmissions.
The side mounting brackets on the X-member offer elongated holes to accept all popular aftermarket transmissions and the most favorite GM transmissions like PowerGlide, GM 4-spd, GM 5-speed, GM 6-speed, Tremac 5 & 6-spd, 350, 400, 700R4, 4L60E and 4L80E.
A slip-fit connection between the tubes allows for disassembly and welding to fit your trans mount position. The multi-position transmission crossmember is actually in three pieces. It comes with the center trans-mount pad not welded to the outer tubes. This way, the two outer arms of the crossmember, that bolt to the X-member's slotted holes, can be shortened (to fit inside the center pad tube) as they slide toward the rear. The center mount can then slide back over the outer arms of the crossmember (tubes) and be welded together. This is an adjustable one-shot deal that will fit just about any transmission length. The center pad can also be turned backward or upside down for another couple inches of movement if necessary. The chassis is also wiring and brake line friendly. The 1 ½-inch diameter round holes (through the ends of the X-member) as it meets the rails are for brake lines, wiring or whatever. This way those items don't have to go under the frame rails to the rear. They are not for exhaust tubing, since they are 1 ½-inch od tubing lining the holes.
At the rear of the chassis, you'll notice we've changed the way our tubular crossmembers attach to the rails. We no longer weld the crossmembers to the inside of the chassis rails, only. The two 1 3/4-inch X .120-inch wall D.O.M. tubular crossmembers that actually go all the way through the chassis and are welded on the inside-and-the outside of the chassis rails. They are the forward 4-link crossmember and the crossmember over the rearend for the antisway bar. This allowed us to hide the rear antisway bar inside the tubular crossmember over the rearend. The new through-frame design adds additional strength to the forward 4-link crossmember, where the torque is transferred to the tires and the road. This was a major change in our design of the new chassis. We now have the super strong center box-tube X-member connected to the forward 4-link thru-frame crossmember so you can put the pedal to the metal with a smile on your face! The arm coming out of side of the frame rail just above the rotor is connected to the ¾-inch diameter thru-frame antisway bar.
We also have a new Panhard rod design behind the rearend housing. The new longer and lower Panhard rod is now parallel with the axle housing which lowers the actual roll-center of the chassis. We call this our Low Roll-Center Panhard bar. You have also have the option of using our Panhard bar over the top of the (rearend) housing. We made our Low Roll-Center bar a standard feature on our tri-five chassis.
The IFS (alignable at home or frontend shop) features an 11-inch GM disc-brake package utilizing '67-72 Chevelle front-steer spindles with bolt-on steering arms, 11-inch GM rotors (retaining your stock 5-on-4 3/4 wheel bolt-pattern), GM calipers (2 15/16-inch diameter piston), and GM balljoints. The 2 X 4 X .188-inch wall box-tube front crossmember holds D.O.M. steel tube 1 1/4-inch od X .156-inch wall lower A-arms and 1-inch od X .156-inch wall D.O.M. steel tube upper A-arms. A '79-93 Mustang manual rack-and-pinion steering unit connects the front steer spindles. Aluminum double adjustable coilover shocks are standard items on our tri-five chassis. They adjust rebound and compression with a twist of a knob. These adjustable coilovers are the only way to go if you like to "tune" your suspension for optimal performance
We give you at least 3-inches of stance adjustability at the rear with our multi-hole mounting brackets for either coilover shocks or ShockWave air springs. Both styles of brackets shown: our 3-hole Standard Street Rod Bracket or our adjustable multi-hole Drag Racing Style Bracket will accept coliovers or ShockWaves. The Drag Racing Bracket offers more adjustment, about 4-5-inches. Both upper brackets have a fixed two-position non-adjustable mounting point.
We offer additional holes in the forward 4-link mounting brackets to adjust the instant-center. Adjusting the forward ends of the bars closer together will help lift the car at the point where the bars intersect (if lines were drawn to the point where they intersect). This changes the weight transfer and the tire bite to the ground. This design is not intended for full blown racing. We just gave you a couple of extra holes for adjustment so you could possibly find a better launch. It will work just fine under your street vehicle without adjusting
Looking down from the top at the forward 4-link bracket connected to the crossmember, shows the beefy connection we build into our chassis. The body-mount bracket and crossmember and the major center chassis X-member all come together to take all the torque any BB can produce
Up front, the stock 115-inch wheelbase chassis IFS features a 2 X 4 X .188-inch wall box tube crossmember that holds 1-inch diameter X.156-inch wall D.O.M. tubular upper A-arms and 1 ¼-inch diameter X .156-inch wall D.O.M. tubular lower A-arms. The ’67-72 Chevelle disc brake spindles hold our standard GM 11-inch disc brakes or your options are 12-inch GM discs, Wilwood super stoppers with drilled and slotted 12, 13, or 14-inch rotors! Manual rack-and-pinion steering or optional power rack will make your shoe box handle like a slot car. Notice, the aluminum coilover shocks and the 1-inch diameter antisway bar are featured on this chassis for handling the factory couldn’t give you back in ’55.
Our new distinctive stainless chassis tags will be on the front of the crossmember on all of our chassis and IFS.
Looking at the inside of the right front upper tower construction, shows that all of the crossmember components are pulse-tig welded together. The .188-inch wall box-tube construction holds the upper-and-lower tubular A-arm cross-shaft, while the tubular motor mounts connect between the chassis and crossmember for more strength at the front of the chassis. Notice how the inside upper-tower is triangulated and totally tig-welded to the chassis rail.
The lower A-arm offers two lower coilover mounting holes for stance adjustment, while the ’67-72 Chevelle spindle features custom Jim Meyer removable steering arms. We also offer optional vented rotors that are drilled and ball-milled.
You’ll love our adjustable multi-hole lower Drag Racing Style Bracket (shown here). It will accept coilovers or ShockWaves. Notice the 2-position upper-and-lower mount, plus all the holes in between. Combine this with the IFS adjustability and you can get the stance you like best. Remember we are the only manufacturer to offer 4-corner adjustability about 4-inches.
To lower the tri-five stance, Jim has engineered an additional 1-inch step over the front suspension and an additional 1 ½-inch mandrel-bend over the rear end. We offer either a mandrel-bent rise over the rear suspension or a fabricated rear frame-section over the rear end (with flat angles). Notice the ¾-inch diameter antisway bar goes through the inside of the 1 ¾-inch diameter wall tubular thru-frame crossmember. The forward 4-link crossmember and the antisway bar crossmembers are thru-frame crossmembers to strengthen the rear of the chassis.
Looking at the front-and-rear frame horns on the frame rails, you can see the bumper-bracket mounting holes are in their stock locations. The rear holes are “tube lined”, while both front-and-rear have non-threaded holes (designed for nuts/bolts).
A stock tri-five chassis never had this kind of support in the center between the rails, in fact GM had only 2-crossmembers and nothing in the center. A solid, non-flexible chassis is good for convertible bodies and it will give you sports car handling, stopping and steering. Add power disc brakes and antisway bars to this chassis and you can drive circles around any stock tri-five.This is what the factory couldn’t give you! The Standard rear 4-link are 18-1/2-inches center to center. Notice how every crossmember connects to the main X-member for all the torque you can give it.