Stock exhaust

[videoguy009]

I bought a stock dual muffler for my Thing.My setup is as follows
1776
110 cam
35x40 head
1.1 lifters
40mm hpmx centermount carb
69mm c/w crank
019 bosch dist

The car runs good and is not restrictive on the top end.I was thinking of dual 40mm hpmx carbs to give me better gas flow for each cylinder and I hear the 110 cam will like this.The center mount is a bit iffy in this respect.Will my car run the same except for a little more torque and hp.Do you think the exhaust I have will work with this setup where it worked good with the center mount?I know it my be a little restrictive but the car is used as a daily driver mostly around town.BTW I had a thing shop header on it and it was too loud for my liking.I really don't notice any difference in performance between the two.

[Marc]

A mild 1775 is close to the largest displacement that can get away with a stock exhaust. You didn't say if you have a gas heater/J-tubes or heater boxes, stock heater boxes are also a limiting factor which keeps you from getting the most out of a header.
Ordinarily I'd automatically go with a larger exhaust system with bigvalve heads and dual 44s; you're not quite there (I'm assuming there's little to no port work on the heads) and for your intended usage the stock exhaust system should be adequate.
The main advantage to duals (even dual 1-bbls) over a center-mount is that they aren't susceptible to the flat spot on acceleration which can be a problem with the single carb setup. Driveability should improve, and there's even the potential for better fuel economy since you may be jetted on the fat side now.

[videoguy009]

Gas heater with no port work.