can you guys please tell me what i can do to get good performance out of the slant 6, but keep gas mileage in the mid 20's? the guys over at moparchat.com didn't really answer my question.
my car is a 1970 dart swinger with the 7.25 rear end, disk brakes on the front, and everything else is stock. what would happen if i put a 4bbl carb, headers, and dual exhaust on it, maybe a cam also? what kind of gas mileage will i be getting with those upgrades and a light foot? will i need to change the rear to a 8.25? i'm not going to be burning too much rubber(probably none at all), and all i want is to liven the old girl up. give me good acceleration. i'm not racing so all out speed is not as important as gas mileage. right now it's down right embarrassing how slow the it is coming off a stop light! please help me out! thanks.


casey

If you just dump on the 4 barrel and all the other stuff and if your car has 2.76 gears you'll get the same disappointment most V-8 guys get when they dump performance stuff on their stock engine a bog on take off or the low end...

Personally I dropped the shorts on a 318 powered 1972 Duster at the stop light a couple years ago with a bone stock 1 barrel slant six because I had a good 1st gear ratio in my 3spd manual and 3.21 rear gears...(and still was pulling in 21.5 mpg)...

You'll want to 'match' all the components and make the power band more useable to you at your normal driving habits. Heck if you want some pep and keep your mileage along with using the stock cam, you can go to a super six and use a 2 1/4" single pipe and that will be ok too...the drop-off occurs when you plunk $1000 for an intake a 4 barrel carb, tuning the carb, kickdown linkage, headers, exhaust work,cam, then find you'll then need to plunk another $500 for the stall convertor and a set of 3.XX:1 gears to make up for the bigger cam and then maybe even a few more $$$ to get the 8.25" rear to hold up to the extra HP you just made with the ad ons....


Sorry to say once you 'pep' it up keeping your foot out of it becomes very hard to do....(not sure why the 1 barrel car sits in the shed while the 4 barrel Hpak car gets driven daily )


Wait for a few others to chime in before making an educted decision about which path to take.

-D.Idiot