AMC 401 build

Saltwater Cowboy

I have a 360 with a broken rod that I was going to build but a 401 came my way (cheap enough that I can't say no). The motor ran like a top when it was pulled so I am not going to do a lot to it before I drop it in. Here is my question, the 360 came with R4B intake with a stock Q-jet turned backwards, RV cam (don't know the specs but I will get them), fenderwell headers, and Ford Mallory Ign. Can I use these parts on the 401? Is the Q-Jet enough carb, should I use the stock Motorcraft 4 barrell, or Truck Avenger? Is the stock cam in a 401 the same as a stock 360? Are the heads the same? Both are late '70's motors and they came out of Cherokees. Thanks for the info

tufcj

Everything will swap. Definitely keep the R4B, dump the q-jet. I have no experience with the truck avenger, but I hear it's a good carb. Heads are the same, the 401 has a slightly bigger cam from the factory. Bob tufcj

ironman_gq

the q-jets were good carbs but hard to work on compared to the other carbs. They came in either a 750 or 800cfm version depending on if they were on a car or truck originally. If the q-jet works good now I see no reason to spend the extra money on a new carb.

Saltwater Cowboy

Well it looks like I am going to swap the intake, ign., headers, and try the Q-jet out. I don't really want to mess with it much if I don't have too. What kind of HP and Tq numbers do these motors put out anyway?

MoPedal

Saltwater Cowboy wrote
Well it looks like I am going to swap the intake, ign., headers, and try the Q-jet out. I don't really want to mess with it much if I don't have too. What kind of HP and Tq numbers do these motors put out anyway?

this would be a good link to go to for some of your answers. http://en.wikipedia.org/wiki/AMC_V8_engine#401

AMX69PHATTY

401 cam is a little ""bigger" as mentioned.
It has more lift & "dual pattern" duration, different exh & int,
where the 304/360 cam is a single pattern.

AMC Cams from 1973 TSM

304 / 360

14.75° .... BTDC Intake Opens
68.75° .... ABDC Intake Closes
263.50° ... Intake Duration
0.266" ..... Intake Lift - Cam
0.426" ..... Inatke Lift - Valve

56.75° .... BBDC Exhaust Opens
26.75° .... ATDC Exhaust Closes
263.50° ... Exhaust Duration
0.266" ..... Exhaust Lift - Cam
0.426" ..... Exhaust Lift - Valve

41.50° .... Valve Opening Overlap

401

25.57° .... BTDC Intake Opens
90.75° .... ABDC Intake Closes
296.32° ... Intake Duration
0.286" ..... Intake Lift - Cam
0.458" ..... Intake Lift - Valve

80.80° .... BBDC Exhaust Opens
42.75° .... ATDC Exhaust Closes
303.55° ... Exhaust Duration
0.286" ..... Exhaust Lift - Cam
0.458" ..... Exhaust Lift - Valve

68.32° .... Valve Opening Overlap

Saltwater Cowboy

Alright, I got the cam out of the 360 and it is a speed pro 1026R. 204/214 duration @ 0.050, 448/472 lift, and 110 lobe sep. I don't see a reason to put this in the 401. The reason being there is not enough to gain over the stocker. Besides I think a stock 401 with a R4B intake, headers, and Mallory ign. should be more than enough power for a CJ 7 with 40" boggers. I am now thinking that the HD rear output for my Dana 300 would be a good idea. With these upgrades what kind of power should this thing put out anyway?