Chop Height
Proper chopping height really depends on your taste, your size and the amount of time you are prepared to engineer the final product to make it safe and usable for a wide variety of drivers. Being 6'2", Chopping tops has become a bit of an addiction. I want to be comfortable, but still have a cool ride. Then I have to engineer it so my 5'0" wife can drive it also.
Here are the lessons I have learned. Maybe one or more of them you might find helpful.
1. Determine how far back you want your seat to sit. Usually your inseam is the correct distance from the bottom of the gas pedal to the crack of the seat. You know, where the back of the seat and the bottom of the seat come together to suck the change right out of your pocket. Mark that spot. That will be the middle seat adjustment and mount point.
2. Determine the seat you are going to use. The most comfortable seat angle (and the one used by the factory) is 105 degrees - NOT 90. That's just in case you decide to build your own bomber seats, don't use 90 - they hurt.
3. Build a riser for them. You're going to want to remove them at some point, so make them removable. I normally use 1 1/2 x 2 inch tube stood up edge - just one per side - so my ratchet will fit inside the tube to tighten down the bolt from the seat adjuster. - Then here's the secret - put a 2" block under the front of the riser. Believe me, this makes all the difference in the world later. Wait to final mount to floor.
4. Go to the bone yard and get a seat adjuster and runners - Front buckets out of a minivan usually have what I need and they usually charge me 5.00 for a set.
5. Mount to the bottom of the seat.
6. Set adjuster to the middle adjustment (there's usually 7-9 settings, just pick the middle one)
7. Mount the seat to the riser. (This is where you realize how important it is to have a tube big enough to fit an air ratchet into)
8. Locate the seat crack to your mark, then mount the seat and riser to floor.
Sit in the seat. Your sight should be centered in the windshield. The seat will now go back 6 inches for taller friends, who will now also be centered in the windshield and forward 6 inches for shorter drivers who will also be centered in the windshield due to the seat continuing to go up and forward.
After this is done, then figure out where the roof should be in order to give you no less than 3" clearance for your head. Now you have a vehicle that can be comfortably driven and sold to a myriad of folks because now everyone fits and is probably chopped WAY more than you thought you ever could.
My last Model A sedan, I chopped over 7" and my 6'6" friend drove it to Detroit (over an hour away) comfortably for a few shows and I sold it to a guy who was 6'2 and nearly 300 pounds who was THRILLED about the headroom in a chopped car. My current Plymouth is chopped 8 3/16. I don't think the windshield is legal, but I still fit easily in the car.
Just a few things I've learned along the way
Bruce
