Anyone have any suggestions about reinforcing the chassis. I was thinking about welding an "X" into the chassis behind the rear axle, since the fuel tank is going to be in the trunk. As well as possibly steel bars or pipes along the sides of the framerails, since nothing can be welded accross due to the driveshaft. If either of those are bad ideas, or someone has a better idea, please post and inform me.

roll cage would probable be best on a full frame car

how many point cage would be best? i mean i could care less how the car looks, i just dont want to invest money into performance then have the chassis go and twist on me.... 502 under the hood.

Just bracing the rear section of the frame wont accomplish much at all. as JYD said .. add a 6 pt. cage min. And even then it will still twist " if " the car hooks.

As was stated above, bracing the rear section of the frame behind the rear end will not strenghten the frame at all. There is virtually no force applied to the rear section of the frame in a coil spring-equipped vehicle. (Unless, of course, if you do a gigantic wheel stand and bang the rear of the frame on the pavement.)
I don't believe that adding bars alongside the frame rails will help much either. A better idea would be to box the frame, as this will strengthen the frame significantly. The ultimate fix for frame flex however, is a complete roll cage - at least an eight or ten point item.

Heres what i did, rewelded the entire frame, boxed frame from tranni mount to rear bumper, supported the upper and lower rearend arm mounts, braced in the rear cross member and ran a tube between the upper rear spring perches. Didn't want a cage so i did all i could do. Ralph

Originally posted by Ralph67:
Heres what i did, rewelded the entire frame, boxed frame from tranni mount to rear bumper, supported the upper and lower rearend arm mounts, braced in the rear cross member and ran a tube between the upper rear spring perches. Didn't want a cage so i did all i could do. Ralph did it make a difference ?

If i were to use a cage, the places where the bars go through the floor to be welded to the frame, how big should those holes be? snug against the cage bars? or leave some room for the frame and body to move a little, like 1/4 inch around the pipe?

Unsure how much it will help the car is in the body shop as we speak, but if it means anything when the chassis parts were going back on and the frame was being moved it sure didn't flex around like it did before. I know it won't be as rigid as a cage but short of tying the rails together with an x brace if figured its gotta help some. Been building stock cars for 20 + years and i've found a nice rigid frame structure is a good start.

If i were to use a cage, the places where the bars go through the floor to be welded to the frame, how big should those holes be? snug against the cage bars? or leave some room for the frame and body to move a little, like 1/4 inch around the pipe?

Cut out the floor pan enough so you can get the welder in and buzz in the tube to the frame. Then take some sheet metal and cover up the hole, leave about 1/16" to 1/8" clearance around the tube and seal with silicone.

alright, ill take that into consideration if i decide to put in a cage, thanks

A 6 point or better yet an 8 point will do wonders, ask me how I know..