The Stovebolt Site Forums The Shop Area Paint and Body Shop Best method to cut floor to accommodate high hump

As the title states, I am looking for information on the best method to cut the floor so I can add the high hump, so I can install my SM420. This work will be done to a '65 3/4 ton Chevy.

I don't have a torch. I do have a sawsall, grinders and cut-off wheels. I don't want to cause a lot of sparks, to start a fire. But I also don't want to be cutting all day. Okay, that was an embellishment, it wouldn't take all day.... Is it easier to get it from underneath, inside the cab, both? I understand being underneath will be messy with material getting all over me, but it may have to be that way. So from you pros of modifying sheet metal, in your experience, what method to cut did you like best?

I plan to remove the seat, and the sound deadening material in the area of the factory "Stamp" in the middle of the cab so I have a good line to cut against and room to do so. I won't cut to the outside of the "stamp" as that would leave the hole too big and nowhere for the high hump to sit and bolt to, so I plan to leave 1-1.5 inches from the outside of the stamp, or whatever the measurement is on the hump itself before the radius.

Short metal cutting blade on a Sawsall will keep the sparks down. Go from the top after drawing a precise line to cut on. Triple check underneath before starting your cut. 🛠

I think I'd try a sawzall with a sheet metal blade (lots of teeth per inch). There will probably be some spots you won't be able to get to with that, but you could switch to a cutoff wheel on a die grinder for (possibly) improved access. That would cause lots of sparks, but unless you're soaked with gasoline, there shouldn't be a problem with fire. But in terms of safety, always have a fire extinguisher handy. And if you're cutting from underneath, be sure to wear a full face shield.
[shoot, Martin beat me to it ]

Sawzall if you don't want sparks. From inside the cab.

I've learned the hard way that grinder sparks are destructive to glass and to vinyl upholstery.

Thanks Martin. I'll be replacing the clutch while I'm at it, so I'll make sure all dangly's and what-nots are clear from the cutting zone while the bell housing is out. As I wrote the OP I was thinking short metal cutting blades might be the best route, and you confirmed it.

Dang, you guys are quick. I was responding to Martin and hit "Reply" and saw more responses. Thanks everyone for the pointers.

Wow!
Less than 20 minutes and you have an answer!
Where else will you find info that fast!

Don

That's what I was thinking too! It's great!