304 engine help

[rr41mag]

Hello all, I am going to be in the market soon for a CJ5 with a AMC 304 . When I purchase it I want to go through the motor completely. Unless of course it is in excellent shape. What I eventually want to end up with is headers, aluminum intake, performance cam, and new carb. Do any of yall have suggestions on which I should choose? Ex: size/model of carb. Specific cam? This jeep will be street driven 95% of the time and I just want more performance without having to drop a V8 in it.

 

[CJim7]

Uh...the AMC 304 is a V8
Get it first, drive it, and see how you like it. There's a multitude of upgrades you can do to the AMC engine....lets see what you end up with first

 

[rr41mag]

Oh sorry bout that, what I was referring to was having to drop in this 350 I have for more power. But i will do that. Maybe one at a time like headers, then intake, etc, etc

 

[Jimbos76cj]

When you get it home either rent or borrow and compression tester and see how tight the motor is. That will stop you from dropping a ton of money into a turd motor.

Normally the best way to start off with a AMC 304 is a decent quality HEI and get rid of all the ignition components. Then a intake and carb.. You don't have to get crazy on the size of a carb.. I'd stick around 650cfm tops. The your left with headers and cam.

If the AMC 304 is to worn Id look into gettin a 360. This way you can keep the same motor mounts, Transmission , radiator, etc etc.. You go to a 350 and your looking at about 500-1000 in adapters SBC specific parts.

Now with the power being upped keep in mind you should have a AMC20 rear that will break a shaft pretty quick with more power and bigger tires. And when a 20 breaks in it's normal spot the wheel will simply fall the heck off. Look around and read up on the AMC20 . Your about to embark down the long and winding road of upgrade a part break another..
Upgrade that part then break another and on and on and on.

Good luck and keep us up on it.

 

[BusaDave9]

What type of driving do you plan on doing with this CJ? If you do a lot of off roading you can get an RV cam that gives plenty of torque at low RPMs. Or you can get a cam to improve the top end. If you plan on using the Jeep on and off road I think the cams that come with Jeep 6 and 8 cylinder engines have a good powerband. I had a CJ7 with a AMC 258 i6 / 4.2l strait 6 and that thing could crawl over rough ground at idle speed without giving it any gas.
I now have a '79 CJ5 with a AMC 304 that has an Edelbrock 2132 cam. I love my AMC 304 but I don't try to squeeze power out of it. I get plenty of power out of it.
I guess I just need to know what you plan on doing before I tell you how to build your engine.

 

[rr41mag]

Itsgoingto be my daily driver. The off roading will be when I hunt.

 

[lxlmariuslxl]

I ran mine just like you are thinking, AMC 304 with the 4bbl and alum intake and headers, She was crazy and full of power. Good mpg if I kept my foot out of it. And yes I did twist the AMC20 shafts which led to 1 piece shafts. Loads of fun.

 

[BusaDave9]

IMHO the best improvement to an AMC V8 is to install HEI ignition. Get a DUI distributor.
Performance Distributors 40820-BK - Performance Distributors DUI Distributor for 71-91 Jeep® CJ & Wagoneer SJ with AMC 290c.i., 304c.i., 343c.i., 360c.i., 390c.i. & 401c.i. V8 Engine - Quadratec

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It's $300. You can find HEI distributors much less than that (such as $AMC 150 ). All these HEI distributors use GM parts you can get at any auto parts store. They are all self contained with the coil and ignition module in the distributor. For that reason they are very easy to swap in.
So why am I recommending a $300 distributor when a $AMC 150 will do the same? The difference is the drive gear on the bottom. The gear on the cheep distributors will wear out on the cam gear. You can get a cheeper HEI distributor if you swap out the drive gear.

 

[rr41mag]

View attachment 6328I have to settle a couple fincial matters first then I will be seriously looking for a jeep. I'll be looking for a CJ5 with a v8. Thats all it needs to have. I think i've decided I will just go with the original AMC 304 and add the headers, intake, carb, and distributor. Hopefully I can find one thats in need of body work since I don't mind doing the word myself. I have to get my wifes 66 done first.

 

[xena1]

I gotta tell you I bought the Summit version of the HEI. Rep told me it was made by Mallery but what I liked about it was the ability to locate cap in 4 different positions. Unlike the Proform unit which had only one cut-out in base for the cap locator bump. I dont know about DUI but the flexibilty to move the cap around really helps, especially if you have a PS pump in the way.