iron duke getting tired... 350 swap!

[cass]

well i serviced the jeep today to find bad news. i took the air cleaner lid off to find it full of oil. so i did a blow by test to find that it has a good amount of blow by. that then led to a compression test to find 125,120,90,125. the hole with 90 had a darker burn on the plug. it has the 2.5 iron duke in it now.


so anyway i have been joking about doing a 350 swap and now its going to become reality :drool: right now i have a T-4 and Dana 300 . i am going to run that tranny for awhile and see how it goes. i have a sm465 and bellhousing sitting out back in the shed if i have to beef up the tranny. so anyway any input will be helpful. i have been reading for days on the swap and it looks pretty straight forward. i am going to go with the andvanced adapters weld in motor mounts. i have my own welder, chop saw, and torch so fabrication is Limited to my brain :wasted:



i cant find much info on the flywheel or clutch setup. im going to assume i use a stock flywheel from the 350 and stock starter. im guessing i use the clutch disc from the iron duke and pressure plate from the 350 flywheel.

 

[AussieCJ7]

I had the same issue about 4 years ago and went with a 4.0L and AW4 swap out of a Cherokee, If at the time the availability of chev's you guys have a LS1 and 460LE/T700 would have been my choice. Ironically the logic I used for not doing a V8 was I would need new axles eventually so went a drive train that wouldn't require axle swaps. Now I am doing built Dana 44 's front and rear anyway

 

[cass]

ya i know the axles are an issue but i will worry about it when it happens i might get lucky and have them last and then again i might break if first time out. i found a low mile 305 chevy out of a 79 caprice at the junk yard i used to work at. its $350 and has compresion readings of 145 to AMC 150 and has the GM good wrench sticker on the valve cover so it was a reman at one time. this will be the one im going to buy when i have the money.

 

[Old Dog]

IMHO pass on the 305 and get the 350.

 

[cass]

lol we will see what happens when i go to buy a motor. i think a 305 will scoot the old girl down the road just fine. i would still be doubling my HP compared to the old 80hp duke. i still want to retain decent fuel milage as well if at all possible

 

[cass]

i just read that to use the duke bellhousing you have to use a 153 tooth camero flywheel with a 10.5" clutch disc.

 

[cass]

well i know it has been awhile but this project is finally underway. im still runnings the tired old iron duke. its compression is now down on 2 cylinders and has major blow by. i drove it to oklahoma last month to the sand dunes. it did ok out there but had a major lack of power. i only got 10 miles a gallon to. thats not to good on a 1000 mile trip!

so anyway when i got back i took the plunge and bought a 350 chevy motor. it was a running engine. im rebuilding it anyway. it had 110 lbs compression on each hole. i honed the cylinders and all new bearings and rings. while there im putting in a rv cam and new lifters. the block is ready for reassembly. im just waiting on my buddy don to help me put cam bearings in. so here is some pics. i painted the old girl black recently and added a hilift jack. i welded spider gears and locked the rear end in (after i did it i regreted it and would not suggest anyone do this BUY A LOCKER) i have taken it down to Randolph ORV park several times. this thing will just about go ANYWHERE i point it. i love it but im ready for more power and hopfully better than 10 mpg.

 

[cass]

well it is running again!! i got it running friday. i just pulled to old motor out last saturday, so less than a week and shes going again. i ended up going with advance adapter headers and a 600 elelbrock carb (that i picked up for $20 and rebuilt myself) stock intake, stock hei, standard cut to length 8mm wires, 75 amp 1 wire alternator, double roller timing chain and sprockets, RV cam, heads have all new except the castings (machine shop did those), camero flywheel, chevy 2 clutch, stock throw out bearing, stock slave cylinder.

i ended up making my own motor mounts and using some new chevy truck motor mounts (the rubber part) i ordered a 3 row aluminum radiator that will be here next week. the iron duke radiator keeps it cool till you take it out on the highway. so i have been toodling around town and short highway runs. i probably have about 100 miles on it so far. it got a half hour cam break in before i drove it.

i havent really run it hard but DAMN!!! it makes that tired old iron duke look like a briggs and straton. its nice to be able to run 65 without being floored and going down hill with a tail wind.

so anyway here is some pics. let me know if anyone has any questions. i will help with anything i can
1980 cj5 350 chevy conversion from 2.5 iron duke - YouTube