Big Block in a Jeep

[Clifton]

Hey guys, I have been gone for awhile now but am kinda back. I am still stuck in Iraq with along road ahead of me but am planning now things for the old CJ7. Has anyone here put a chevy 454 in a cj7. I have one and a good SM465 tranny and the adapter to the dana 300 transfer. The 454 weighs approximately 175 pounds more than the 258 that is in it now. That may not be correct, just weights from a couple of websites I have read. I am not looking to make a super hotrod out of the Jeep. It will be pretty much a stock 454, probably a edebrock performer intake and a performer cam for a TBI fuel injection as I have a throttle body set up for a big block already. Should have well more than enough torque and horsepower for a CJ7. What I was wondering is will the frame handle what I am about to do to it and will it be worth a flip on the trails, I dont want a big block hindering its ability to climb hills and play in mud or do the fun things that jeeps do. I am not worried about the drivetrain as I will have replaced most of it but the differentials, the amc 20 will have one piece axles in it by that time and both will be regeared. Is this also a major undertaking, I have put small blocks in them before and it is not to bad of a job, but a big block? I was just kinda wanted to pick ya'll brains a little.

[Jeeperator]

A small block is a tight fit isnt it? a bb is a whole different story especially with header fitment and cooling options (bigblocks tend to run hotter than smallblocks). A bit overkill imho but if thats what you want go for it. I have a buddy who put a bb in a yj he just did it because he could. I dont think he takes it offroad. Its more for conversation and show if you ask me.

[peteyg]

I saw a guy with a Caddy 500/Powerglide combo in a flatfender. It was a VERY tight fit, and it had heating problems. Mostly with the starter. GM starters do not like to get hot.

[dadasjp]

Are you married to the 454 idea? Maybe you should look into running an AMC 401 v8 (you can find them in old wagoneers) which should mount in about the same as the AMC 304 v8 which was offered in the CJ7. I'm not an expert, but maybe it's a much easier installation and could get you some serious hp output. I think there's some good after market performance support for the muscle cars that ran that engine. Just a thought.

[tool pimp]

heres a Jeep with a Viper motor
http://www.youtube.com/watch?v=HYcXDwE-4Ow

[inVERt'D]

Clifton,

An in-law was once intending to give me a CJ-7 with a 443 Hemi. Can't remember, but I think it might have been blown (supercharged) as well. This thing had wheelie bars on it. Well, I never got the chance to drive it, cuz a wildfire burned the shed it was in, leaving nothing but puddles of metal where my beautiful Jeep-to-be had been. I was really bummed at the time, but looking back I think it was one thing God did to help me live through my twenties.

If you're not intending to build a super hotrod, then I think a big block is more weight and torque than you'll want in an offroad Jeep. I'd be expecting you to be breaking axles and twisting driveshafts like crazy. Big block Jeeps are for drag racing. FWIW, if I were going big block I'd be looking at a built Ford 9-inch or better, not a Dana 20.

I do think the SM465 is a great choice for a tranny, but if you want a V-8, how about a smallblock 350? Buy a wrecked Camaro with an LS engine and you'll have more than enough power, and good gas mileage too. My .04.

Hoping you come home from Iraq safely, sanely, and in one piece.

David

[Clifton]

Thanks for all ya'll advice

I appreciate all the advice. I am not totally married to the 454, it was just a thought. I am more afraid of ruining the trail riding ability with weight than anything else. I beleive the jeep needs to be regeared. It has the factory gears in it which I beleive are 308's or taller. It also has 33x12.50 Mickey T's on it as well. The 4.2 is not stock and runs reall really well for a 4.2. The bottom end is .10 over, it has a 4.0 HO head with an offenhauser intake and header exhaust, A howell TBI fuel injection system and a HEI distributor from performance ditributors on it. The fuel injectionis awesome, the TBI from GM is the simplest and and one of most efficient fuel injection systems out there upon reliable as hell. It has made the Jeep unbeleivable fuel responsive.

[kirkandsylvia]

Clifton,
I have a 76 full size cherokee with a amc 360 backed by a 400 powerglide, and with a wopping weight of 6200 pounds, that 360 is all the torque and power I need. I think once you get too much under the hood, it become useless and problematic horsepower. The additional weight would eventualy start stressing the frame and suspension components, and we all know, jeeps arent cheep to fix. My 2 cents are to stay with a small block, and keep it simple. You can make up the less ponnies by gearing down.

[Ol Man]

I appreciate all the advice. I am not totally married to the 454, it was just a thought. I am more afraid of ruining the trail riding ability with weight than anything else. I beleive the jeep needs to be regeared. It has the factory gears in it which I beleive are 308's or taller. It also has 33x12.50 Mickey T's on it as well. The 4.2 is not stock and runs reall really well for a 4.2. The bottom end is .10 over, it has a 4.0 HO head with an offenhauser intake and header exhaust, A howell TBI fuel injection system and a HEI distributor from performance ditributors on it. The fuel injectionis awesome, the TBI from GM is the simplest and and one of most efficient fuel injection systems out there upon reliable as hell. It has made the Jeep unbeleivable fuel responsive.

Sounds to me like you need to keep the six and re-gear and go have fun. The in-line six is amazing at low RPM and just grunts along.

[OU812]

I love my 4.0. It drives like a tractor!

[Kodiak Spirit]

Thanx for yer service btw, I would say the 4.0 is good to go, maybe put the money into a sweet T-case or gears instead.

BUT it is nice to have a few ponies under the hood! sometimes it's nice to throw a V-8 in there just because you can, and everytime I meet someone on the trail sportin' a V-8 they also have a big grin... I do think lighter is better, it would be nice to get the power and still be just as light, or lighter than the cast I-6...