MrBR

After my car sitting pretty much for most of the past 6 months due to it suffering from a "carburetor on the intake manifold" I've finally gotten the car in the shop. I plan to save money by sticking to a drive-by-cable 5.3 and keeping my 700r4. Now that this is finally happening and my car might be reliable enough to take trips longer than 2 miles I'm curious to see what gas mileage I'll get. Since suburbans/silverados get 13 in the city and 17 on the highway and I weigh about 1000 pounds less (about the same aerodynamics) what gas mileage should I get in my Impala? I'm hoping for 20 mpg highway but anything is better than the 10/12 I got on average (except for a freak accident of 14, but that was mostly highway).

SKEETS63IMPALA

iTrader: (1)

Not sure what kind of mileage you'll get. That 700r4 should help with highway mileage though for sure. I'm planning on swapping a Vortec 5.3 into my 64 also but I'm just sticking with the original powerglide and probably doing a turbo as well while i'm at it. Goodluck with it, and make sure to do a build thread when you start swapping.

MrBR

I already had the 700r4, that's the reason I didn't buy a 4l60e.

leon phelps

from my experience (a ls1 5.0l in a 65 impala), plan on getting the original tune for the VATS and rear o2 sensors then when you have everything together get a street tune by a company that does lots of them.

I pulled my hair out with error codes to find out the different exhaust needed a street tune.

I would guess at least 20mpg on the highway, and it will be lighter and faster.

good luck.

MrBR

20mpg is basically daily driver fuel economy in my book. Should I trade my flowmasters for stock mufflers?

leon phelps

I send the exhaust out, I was afraid to weld to my nice coated headers. The weld looks like crap, of course.

I wanted quiet, didnt really care about speed or sound. I forget what was put on the car. Ill get under it to see if there is anything on the mufflers.

I know they were 2.5" mufflers though.

psiconversion

iTrader: (5)

My 64 Biscayne had an LT1 with 4L60E and a flowmaster 2 inch exhaust. The engine was stock and we drove it from New Jersey to Charlotte for a Good Guys Show. Car got around 25 mpg on that trip. With that engine and a 3.31 open rear the car went consistent low 14s. Fun to drive. LS3 going in it soon, though.

Jon
PSI

MrBR

The engine should run fine even with the 700r4 right? Should I do a tune once I get it running so it factors in everything done to it?

psiconversion

iTrader: (5)

Yes, it will run fine. As others have stated, you may want to consider a 4L60E, if finances permit, as you wont have to worry about hooking up the TV Cable and you can taylor shift points in the PCM.

Jon
PSI

MrBR

Do you think my 11 inch rotor front disc and rear factory drum
Brakes will be up to task of stopping my car still for this swap?

cbrodine

Yes, they will. But 4 wheel disc breaks never hurt anybody...

What rear end you have in the car now? 8.5 10 bolt?

MrBR

Stock, which leads me to believe I should probably never floor it, especially since I just replaced the seals, it would suck knowing I spent that money just for a snapped rear end.
I know it's neither of those though.

fatboy64

good luck with the swap. im doing the similar swap in my 64, I'm still in the process though


josh

MrBR

I don't know why more people don't do these swaps. Sure they're expensive but you get street able gas mileage, and (after doing calculations) my 1964 impala should be able to beat a 409 425 horsepower 1964 impala. It'll do this with twice the gas mileage and twice the reliability.

leon phelps

you can try to reason with car people all you want but they think it is a sacrilege to change anything. Look at the whole bias tire thing, eventually people come around and the hard heads still buy them.

cant wait to see a vid of it running.


no exhaust

Gen1

Very cool, nice to see one hot rodded up a little.

1989GTA

Just finished warching the Barrett-Jackson auctions. One thing I noticed is that the LSX "restro-mods" were bringing pretty good money. About on par with those that had the original engine. So I think the trend is already in place and for the reasons you cited. A lot of those cars were using the GM LS3 package.

Also from the Barrett-Jackson auction it seemed about every fifth car was a Mustang. It also seemed that a good percentage of those were Shelbys.

MrBR

If I remove my flow master 40s and replace them with stock mufflers will it affect the tune or not enough to matter? I don't dig drone. I tried them for awhile but I feel like I'm flying a small aircraft.

MrBR

Sorry for the self bump but I am really curious about the muffler issue.

leon phelps

if you chance the exhaust, drive it. See if you get any codes.

Then check mileage. It should tell you.

I would have it street tuned. It will make sure everything in OK. I call it a $500 insurance policy that will tell you HP. It will also let you lower the temp the fans come on (if you didnt lower it already).