Average HP/Torque number comparisons?

beyer05

I currently have a stock (headers only) carbuerated 304 in my CJ. I also have a running 360 out of an old waggy (but would probably need a rebuild). I want a strong motor for a trail rig (lots of torque, but still rev when I need it). I know AMC's have good torque numbers but not sure exactly how they compare to a SBC. I am trying to decide how much power I will gain with a motor swap and wich route would be the cheapest or easiest. FWIW, whatever motor I choose, will get TBI and Edelbrock intake. Thanks. Here are my questions: - How much HP/Torque does a 304, 360, and 350 have stock? All 80's models. - What would it cost to rebuild a 360 back to stock specs, with maybe a cam and slight compression bump? Nothing fancy. Economical route, but that will still be a good reliable motor. - Anyone have a fresh 401 they would like to sell me?

tarior

A stock rebuilt AMC 360 is comparable to an LT-1 350. Add a cam, headers, intake, and a little head work, and few production SBC's can keep up. Oh, don't forget to address the oiling system.

beyer05

I am pretty sure an LT1 is about 300 HP. I have found these numbers on another site for AMC's, but not sure on accuracy.

1980 AMC 304 - 125/220
Post '72 AMC 360 - 175/285
1971 AMC 360 - 245/365 (probably a gross rating)
AMC 401 - 215/320

Is the LT1 rating a gross rating (crank?), because the AMC stuff is net (rear wheel?).

If I could get within 50 HP of the LT1 (not sure on torque) with a fairly stock 360, I think I would be happy.

Anyone have experience with this company

http://www.flatlanderracing.com/rebuildkitsamc.html

http://www.rebuilt-auto-truck-engines.com/long_blocks.htm

tarior

'70 and '71 360's with 4bbl and dual exhaust were 290hp/395 lb-ft, conservatively. '71 401 was also conservativley rated at 330 hp. I suspect that an LT-1 probably has a bit more of an aggressive cam than a stock AMC 360. :-|

pablorg

tarior wrote
A stock rebuilt AMC 360 is comparable to an LT-1 350. Add a cam, headers, intake, and a little head work, and few production SBC's can keep up. Oh, don't forget to address the oiling system.

What are the things to address on the oiling system? I have an AMC 360 to which I am installing the Edelbrock heads, intake, and 600cfm carb.

tarior

There is a whole section of this website dedicated to AMC oiling, check it out. :t:

tarior

What are the things to address on the oiling system? I have an AMC 360 to which I am installing the Edelbrock heads, intake, and 600cfm carb. I would recommend a bigger carb, say 700-750 cfm.

beyer05

tarior wrote
'70 and '71 360's with 4bbl and dual exhaust were 290hp/395 lb-ft, conservatively. '71 401 was also conservativley rated at 330 hp.
I suspect that an LT-1 probably has a bit more of an aggressive cam than a stock AMC 360. :-|

I am assuming this is gross HP and not net?

tarior

AFIK, all US manufacturer's hp ratings pre-1972 were gross

beyer05

So... a late '90s LT1 is around 300 HP net? And a mid '80s 360 is around 200 Net?

tarior

Don't forget that a 90's LT-1 is EFI, no smog pump, whereas an '80s 360 (or anything else from the late '70's or early 80's is very de-tuned and burdened with low-tech emission controls). Believe me, take your 360 and do a nice rebuild, and 300 net Hp is VERY easy to get, for around a couple grand.