i do remember him saying something about a 3500 stall in this car but it was russian to me at the time. I was a little overwhelmed to say the least. Where is this and how can i check this?
Aha! Your loosing about 15-20% of your power right their, which is why you say it feels like it is straining. Odds are, your 40 mph cruising rpm is right around the stall point of your convertor. That is way too much convertor for a CASUAL street driver, IMO. However, combined with the large sump oil pan, single plane intake, and traction bars, I'd bet you may have a fairly radical cam shaft profile, which also is counter to casual street cruising, but I'm getting ahead of myself.
The only way to physically verify the convertor is to remove the transmission, then the convertor, and look for the manufacturer's part number. The torque convertor is a large, enclosed, donut looking thing between the engine and transmission, inside the transmission case. In the car you can make an educated guess at it, but without a functional tach, all you can do is kinda guess. With the car in idle and low gear, stomp on the gas and watch (or in your case listen) to the rpm and relate that to when the car starts to physically move. If it moves right away at a fairly low rpm, then you have a low stall. If it hesitates a fraction of a second while the rpm climbs and then takes off like a shot, you have a higher stall convertor. If you have a dwell tach, you might be able to substitue that, but I'd call MSD and ask for the shunt that will allow you to hook up your in dash tach.
Getting back to the first paragraph, I hate to tell you, but it is starting to sound like you bought yourself a psuedo-race car wanna be. It is more radical than a restored street cruiser, but isn't an all out racing machine. I'm sure it is pretty darn fast, but as you've noticed, it isn't the most street friendly cruiser either. With 4:10 rear gears, as you noticed, it will tach up fairly high just cruising around town. The only way to correct these items is to replace the convertor and replace the gears. However, because of how the engine may be built, it may not be just that simple, as changing to more street friendly gears may also mean you need to change the camshaft and intake to better match the new gears. It is also possible, as others have mentioned, that it has a manual valve body in the transmission. When you put it in drive, can you hear it shift through the gears?
The gas smell could be a few things from mis-adjusted float levels in the carb, to being over-carbed and not burning off the fuel at idle, to a physical leak in the carb that drips onto a surface which then evaporates, which is why you can smell it but not see it.
Another recommendation, find a local mopar club, join it, and make some new friends. You are going to need some their assistance on small things like tuning advice as well as some recommendations on big things, like if you want to change your car to a more street friendly cruiser or leave it as race beast. These club members are going to know what shops are best to do business with and which ones to stay away from. As a former Vette owner, I'm sure you can appreciate that you don't want to pay money to just any schmuck working on your car who doesn't know the difference between a torsion bar and a torsion spring. Plus just hanging out with other cars people is a pretty good time over all.