I have these racing seats, and due to the design of the sunny 310 floor, the seats sit too high, there isn't really more than a cm or 2 that they can be lowered without modifying the floor.

if i cut the front ribbed channel that the seats mount to to put in something more flat, am i going to have problems with the chassis?

if I can cut out the part of the floor and weld flat plate back in that would seem to solve the problem, so maybe i need some tips from people that replaced the commonly rusted out floor boards in their dattos

I need help the engine will be installed soon and i'll have a car with no seats to drive.

no problems with doing that, it will be alright. If you really want it strong, you could weld a couple of sections of RHS across from the tunnel to the inside of the sill (?don't know how else to descibe it) to mount the seat slides/runners on after you've done what you describe. Then the area will be stronger than factory.

Yeah, definately, just do it!

Jump straight into the deep end, everything else will seem shallow after that.

Like L18_B110 said, make sure you strengthen/brace things on the oppsite side. It's better to over engineer than under engineer!

I might as well, i'll learn something by doing it.

I was researching dow to MIG sheet metal, so I think that after i get some thin wire, i'll practice on some scrap sheet metal, anyone remember what gauge sheet they make datsuns out of?

for god's sake, brace the car first.

park it on VERY level ground, and tack some supports - from the underside of the floor around where you'll be cutting - to the ground.

that way, there's NO chance of the body sagging when you jump in to fit the seats with half the floor cut out.

small, but vital point.

Made me think of something interesting, i can use something wheeled like a built up furnature dolly to position the seat exactly where i want it.

I'll give it more thought a since i wont have the car for a day or 2

My main worry is that since i'll be taking out some of the body ribbing that goes across the chassis that i'll have to add in more cross bracing. I'm thinking of adding a roll cage at the same time.

I also noticed that the ribbing in the floor isn't stamped all the way through the floor, which means there are big air pockets. I may just have to trim the top layer out and re-enforce some.

I have to get the car back and pull the carpet out.

Probably better of getting different seats!

If you have little experience welding, this is not the palce to start.

Welding cars is a bitch. The chances of creating holes is high. If there is any under body sealer, this will have to be removed because it burns (starts a fire.

If someone tells u welding car panles is easy, they probably don't understand the word
penetration and the word distortion.

Seriosly, get some other seats.

I've welded cars before so i know how much of a pain it is. I have a better welder now and the right wire.

If I can't do it, I'll find someone who can.