Engine Transplant

[spaceduster]

Does anyone know the largest mopar engine I can drop into a 1973 Plymouth Duster without modifing the engine compartment?

[Matt167]

Probably looking at a 340 or 360.

[Don Shillady]

Just an old story with maybe some modern significance. Around 1985 I was shopping around for a family car after our Volare Slant-6 finally wore out (since it had a manual 4-speed in a wagon I am now qualified to drive a school bus!). I saw a 1970 7-passenger Plymouth wagon on a lot with only 9,000 miles and a perfect interior with perfect paint, so I asked for a test drive to take it home to show it to my wife. It was low on gas so I put in 5 gallons for the test drive. It had a 360 and could really haul! However on the way home to show it to my wife I could literally watch the gas gauge fall as I drove! It must have gotten all of 8 mpg. One of my coworkers had that same model and he said he seldom got over 11 mpg. Later I worked on some 360 heads and the intake ports are huge! So, yes a 360 will really move it along, but be prepared to buy gas for it! About a month later we bought a Pinto wagon with a 2L OHC engine instead, back in the years when the kids were small and we needed an economical family car. I still have great respect for the performance of the 360 but man oh man they do use gas!

Don Shillady
Retired Scientist/teen rodder

[Matt167]

Originally posted by Don Shillady
Just an old story with maybe some modern significance. Around 1985 I was shopping around for a family car after our Volare Slant-6 finally wore out (since it had a manual 4-speed in a wagon I am now qualified to drive a school bus!). I saw a 1970 7-passenger Plymouth wagon on a lot with only 9,000 miles and a perfect interior with perfect paint, so I asked for a test drive to take it home to show it to my wife. It was low on gas so I put in 5 gallons for the test drive. It had a 360 and could really haul! However on the way home to show it to my wife I could literally watch the gas gauge fall as I drove! It must have gotten all of 8 mpg. One of my coworkers had that same model and he said he seldom got over 11 mpg. Later I worked on some 360 heads and the intake ports are huge! So, yes a 360 will really move it along, but be prepared to buy gas for it! About a month later we bought a Pinto wagon with a 2L OHC engine instead, back in the years when the kids were small and we needed an economical family car. I still have great respect for the performance of the 360 but man oh man they do use gas!

All mopar V8's get horrible MPG compared to the other American V8 companys.

Don Shillady
Retired Scientist/teen rodder