High Power with Factory Frame

[392Hemi]

Any of you running 650+HP (I know that's high power for some people)

on the factory frame? I know the boxing option is out there, I'm prepared to do some boxing work near the front suspension and rear axle.

Only owned the truck for 2 weeks now and got it torn down for the mustang ii front suspension.

[Rickysnickers]

I'd suspect the frame would be able to tolerate that for a little while, but not too long. I'd probably completely box the frame if it were mine.

[mr48chev]

I'd go along with boxing the whole length of the frame and think about putting in some sort of X member setup.

I've been around these trucks for a long time and have seen a lot of them with blower motors or big blocks that got ran hard and haven't seen frame problems from the horsepower or hard driving.

The frame problems I have seen came from poorly designed or done modifications, Including hacking part of the frame away with a torch for clearance or pulling the crossmember under the bellhousing out and not reinforcing the frame. That crossmember is a main part of the structure of the frame but the MII crossmember install should make up for some of that.

I can't think of who right off but a couple of the guys have built seriously strong and great looking frames out of their stock frame and have the photos in the projects and build section. Hopefully someone will show a photo or link before the day is

[1project2many]

High power isn't an issue if you don't have high traction! I'm sure you'll be planning the tub / narrowed rear install which means bet. MII front and narrowed rear, there won't be much "stock" left to worry about.

[OrrieG]

These frames were originally designed to move and flex as the farmers and loggers drove them over the fields, water bars, ditches, etc. I have have mine corkscrewed pretty good over the years. Boxing will make the side rails stronger but I would keep the cross bracing flexible. If you do not allow for some movement the forces will eventually find their own path resulting in cracks from fatigue. Also the stiffer they get, the harder they ride which gets old fast after a few minutes.

As a kid I was told not to weld on the old frames, but to use bolted connections because welding changed the metal and weakened it. Over the years I have seen many welded up with no problems so it may have been a problem with very early (pre WWII) frames.

[Speedbumpauto]

Here's a factory frame, enhanced, but a TF. Boxed over the F-bird clip and boxed in the added 4 link crossmember and it's triangulated braces + boxed in the C notch. BUT....I might get 550 HP on a good day. What the others have said is right. You don't have to worry about it if you can't put it to the ground.

[mphudak]

If boxed and braced correctly it will handle it. Here is one from jalopyjournal.Com that was fully boxed frt to rear, extra crossmembers added in prep for a built 392 hemi. Builder is "65standard" and is well worth a look at his gallary and posts.

[392Hemi]

Originally Posted by Speedbumpauto

Here's a factory frame, enhanced, but a TF. Boxed over the F-bird clip and boxed in the added 4 link crossmember and it's triangulated braces + boxed in the C notch. BUT....I might get 550 HP on a good day. What the others have said is right. You don't have to worry about it if you can't put it to the ground.

wow that's beautiful, good work. I guess the conclusion here is that no one has ran big power without modifying the frame haha.