• DCRC 2024

151 2.5 IRON DUKE power adders

G

gr8outdoorzman

Member
Location
hill AFB
Looking for suggestion on boosting the power on my Iron Duke in a 81 CJ-7. Does anyone on here still run there iron dukes? I have looked at some different cams, intakes, headers. Was really just wondering what people have done that has worked the best for there dollar.

Thanks
 
Greg

Greg

Make RME Rockcrawling Again!
Admin
Location
Grand Junction, CO
I had one in my first Jeep, an '80 CJ5... best mod I ever did was drop a built SBC in it's place. :D

You're probably aware, but that bellhousing has a Chevy bolt pattern. It's VERY simple to bolt up a bigger/better engine and the SR4 transmission will work with it. I was told the stock SR4 trans was weak, but it held up to my abuse and a very healthy 350 ( 400 horsepower ) for a long time. You do need a smaller flywheel/flexplate and clutch, if you go that route. They are out there.

IMO... yank the 151 Iron Duke and toss in a 4.3l Chevy. TBI or Vortec, depending on how complex you want to get.
 
G

gr8outdoorzman

Member
Location
hill AFB
Yeah i have a carberated 350. I am really tossing that idea around. i also have aT-5 that if i went that route will put behind the 350. which like you said i will still need to get the flexplate and flywheel. Would be interested in talking to you more about how much you spent and things you would do differently. thanks
 
Greg

Greg

Make RME Rockcrawling Again!
Admin
Location
Grand Junction, CO
What do you want to know? I'll tell you want I did, mabey that will give you some direction.

I got a heavy duty 4 core radiator built for the SBC from MEPCO (showing my age! :eek: ) to cool the motor. I'm sure you could find something similar from Novak or Advanced, or...

I think I used Advanced Adapter engine mounts, then fenderwell headers and 4" exhaust on each side that ran under the rocker and dumped out the side, before the rear tires. It was LOUD and I hated the exhaust, but it was the easiest way.

I used a 16" electric fan and it did a decent job of cooling, but I had to run the fan in front of the radiator, because it didn't fit between the water pump and radiator. It was a tight fit!

Honestly, I think a 4.3 V6 would be a better candidate. Better weight and power balance and it will fit much better, leaving room for a fan. I blew up my rear axle shortly after getting that SBC running in the Jeep, there went another $1000 after the engine swap.

I started out with a carb, but it sucked offroad. I picked up a Holley Pro-Jection EFI system thinking it would work well, but is it was pure evil. It would quit on me for no reason, leaving me stranded. I hated that EFI system.

If you're stuck on using that 350 you have, I'd suggest gathering the parts to swap on a GM TBI fuel injection system. Simple, proven and cheap.
 
G

gr8outdoorzman

Member
Location
hill AFB
i have been thinking of doing this for a long time...so i already have the bolt-on motor mounts. the carb is a quadrajunk"jet" would like to pick up a nice aluminum radiator. I have a amc radiator that was in front of a 304 and then infront of a 350 w/some nifity hose works going on. my 350 motor probaby won't put out 400hp. but more then my anorexic 151. and i have a set of shorty headers. so alot of the expense is taken care of.

where did you get your flywheel from. does Oreilys or auto zone sell the smaller flywheels or do i need to go with a high dollar ones from advance adapters. or is that about normal price. it seems high to me. but never priced these.
 
Greg

Greg

Make RME Rockcrawling Again!
Admin
Location
Grand Junction, CO
If I recall, I had to use a 10.5" flexplate and clutch with a 153 teeth, versus the standard 168(?) teeth. There is a factory application, like an 80's Camaro, that used them.

For the clutch I used a Centerforce clutch and it worked well. No real need for high-dollar parts far as the clutch is concerned, unless you feel it's needed.

The starter was a different story, a standard starter won't fit due to interference with the bellhousing. I had to order a special starter from Summit Racing that would work with the 153 tooth flexplate and the SR4 bellhousing.

I was able to keep the stock hydraulic clutch master & slave cyl system and I really liked it, much better than the older hinged, mechanical system.

You mentioned the T-5 transmission... will that work with the Dana 300 t-case and the bellhousing you have now?
 
You must log in or register to reply here.
Top