Any advice for a 4.0->4.5 "Poor man's stroker"?

[SC/397]

Geeze, I built a budget stroker for my Commanche in the mid 90's before all the craze and it ran perfect. In fact, better than my '98 Dakota with a 318 in it. The truck got wrecked after about 100,000 miles on that stroker and we put it in my Bro's Commanche and he ran it forever until finally selling the truck. The recipie is simple:

4L block bored .30. .040 what ever it takes. Mine was a '91
258 crank, 258 rods. I had to cut 3/8" off of the snout at the vibration damper. A spacer could have been uses as well.
Cast 4L pistons new. The compression ratio ends up at 9.5:1 with a .030" over bore.
Stock 4L Vibration damper and flex plate/flywheel.
Cam. NAPA "MPG" cam for a 258. No noticeable lope.
Head '90/'91 4L. Complete valve job etc..
Oil Pump, I used the Mopar (Jeep) heavy duty oil pump.
I had the rotating assembly balanced but, it was so close I wouldn't have had to. My truck was a '88 and I usd the stock '88 intake and fuel injectors. I did not recalibrate the computer. I used the stock '91 exhaust header because it looked a better system than the '88 was. My gas milage went from 18 to 17 due to the fact that my foot got a little heavy. I burned 89 octane fuel with no ping. There was a noticable difference in torque over the stock 4L which was no slouch to begin with. It didn't run like a warmed over 360 but like I said, it ran and pulled a trailer with a car on it better than my 318 Dakota. (Of coarse, the Comanche didn't stop the trailer as well as the Dakota did.)

[Carnuck]

I ran the Mexican motor the stroker was based on in my Eagle, then my '83 Cherokee with 17-20 mpg average hwy.

[smacaroni]

Originally Posted by SC/397

Geeze, I built a budget stroker for my Commanche in the mid 90's before all the craze and it ran perfect. In fact, better than my '98 Dakota with a 318 in it. The truck got wrecked after about 100,000 miles on that stroker and we put it in my Bro's Commanche and he ran it forever until finally selling the truck. The recipie is simple:

4L block bored .30. .040 what ever it takes. Mine was a '91
258 crank, 258 rods. I had to cut 3/8" off of the snout at the vibration damper. A spacer could have been uses as well.
Cast 4L pistons new. The compression ratio ends up at 9.5:1 with a .030" over bore.
Stock 4L Vibration damper and flex plate/flywheel.
Cam. NAPA "MPG" cam for a 258. No noticeable lope.
Head '90/'91 4L. Complete valve job etc..
Oil Pump, I used the Mopar (Jeep) heavy duty oil pump.
I had the rotating assembly balanced but, it was so close I wouldn't have had to. My truck was a '88 and I usd the stock '88 intake and fuel injectors. I did not recalibrate the computer. I used the stock '91 exhaust header because it looked a better system than the '88 was. My gas milage went from 18 to 17 due to the fact that my foot got a little heavy. I burned 89 octane fuel with no ping. There was a noticable difference in torque over the stock 4L which was no slouch to begin with. It didn't run like a warmed over 360 but like I said, it ran and pulled a trailer with a car on it better than my 318 Dakota. (Of coarse, the Comanche didn't stop the trailer as well as the Dakota did.)

This is great info. Unfortunately, it seems that I may not be able to do this until next July or August, but I very much appreciate your specs. And I'm really pleased to hear yet another "ordinary" build of a 4.5 hybrid motor (AMC/Chrysler, not gas/electric) that ran well for a long time. There seems to be two camps, one "use only the very best parts or you'll be sorry" and the opposing side "just do a decent build with decent parts and you'll be fine, it's not like you're gonna spray it..." (meaning NO2, not spray paint. I'm probably going to paint mine because an extra two day's labor on the stand is the same as a week or more in the engine compartment.