170ci manual would probably be best on fuel economy and period correct, and 200 next in line... IMO, i wouldnt be doing engine swaps and all that if your going for economy, all that work is going to cost more than youll be compensated by the gas

 

Stick with the six if you are looking for fuel economy because if you go with a V8 you will have to spend a small fortune changing a lot of other stuff which will end up costing you more than the $ for fuel.Good Luck with it!![8D]

 

I agree...if your goal is fuel efficiency, stick with the six! If you do a search in this forum you will find lots of useful information on ways to improve power performance on your stock six. Like nineteensixtysix stated, once you go to an eight, there are many more upgrades you will have to do...it's not a 'should do' it is a must do with the extra power.

Then again, if money is of no concern, then stay on course with the EFI 5.0.

Either way, best of luck!

 

I don't think anybody buys one of these cars for fuel mileage, could be wrong! I'm sure the i6 will run, but when I mash the pedal, I want something to happen! Better build what you are going to be happy with, cost too much to do it twice. If you are really going to restore it, the engine is the last thing you need. Unless it's a rolling restoration, which I've never done. They are right about being expensive to change over to V-8. I have done that! The cost of the engine and transmission is only a part of the swap.

 

look at the forums at www.classicinlines.com there is tons of info on the 6...have fun with it

 

I converted my car from a 6 to an EFI 5.0 and overdrive transmission. I wanted the mileage improvement, benefits of a computer controlled engine, performance of a V8 and wanted to be a little more unique. It does add a lot onto the cost but you can do it on a budget if needed. I did the conversion with basic mechanical skills and taught myself as I went.

If you want a quick and easy solution go for the 6 cylinder engine. If you want a kick in the pants to drive car that is likely more dependable then go with EFI V8. I know some will challenge me on reliability but I don't have to adjust my carb any longer.

Either way you go you will have fun and get plenty of attention driving one of these beautiful classics.

 

Let's be conservative and say that you can go from an I6 to a V8 withefifor only $6K, including changing out the rear end, the front suspension, the radiator, etc., etc, all of the necessary things to make a V8 work in a car that was designed for the I6. And, let's suppose that you could increase your average fuel mileage from 20 mpg to 25 mpg.

At $3.00/gallon, you'd have to drive 200,000 miles to break even, where the money saved from reduced gas purchases paid for the upgradesfor a higher mileage vehicle.

Let's face it, we are not restoring these cars to save money on gas. My own gasoline bills have gone up since I bought a car that I really didn't need, and starteddriving just for fun,even though I have the 'economical' I6.

 

[align=center]
Magnuson and/or Procharger Blowers Kits[/align]


Classic Inlines will be working with Magnuson on the development of an intake manifold suited for mounting the M90 SuperCharger to the new aluminum cylinder head. If possible, the design will incorporate an air to water intercooler so that boost levels can be increased for optimum performance gains.




The Magnuson MP90 is a “State of the Art� supercharger engineered for 3.0 to 5.7 liter passenger cars. It was designed as a compact, flexible supercharger for increased power, quietness, and reliability without adversely affecting fuel economy. The M90 has proven itself in a number of original equipment and aftermarket applications. This latest version incorporates “S Port� technology and a built in bypass for unparalleled performance.

[align=left]The Magnuson MP90 is a “State of the Art� supercharger engineered for 3.0 to 5.7 liter passenger cars. It was designed as a compact, flexible supercharger for increased power, quietness, and reliability without adversely affecting fuel economy. The M90 has proven itself in a number of original equipment and aftermarket applications. This latest version incorporates “S Port� technology and a built in bypass for unparalleled performance.
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^yeah, but on stock brakes? Stock C-4? The cost/benefit ratio goes bad quickly again.

Me? If it is an I6 - keep it stock. If you need more performance - sell the car & buy a V8 one.

 

I would put disc brakes on if i did that.