351m redline

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Sep 4, 2007 | 03:55 PM

c_cort

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351m redline

What RPM's do these engines top out at. It's a Jasper rebuild with abut 60k on it. and it seems to not like anything over 3500 rpm's is this the redline or is there something not right

Sep 4, 2007 | 04:05 PM

80broncoman

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From: southeren Oh

I think trhe hp peak on a stock 351M engine is around 3200-3400RPM. Which means that if you spin it to 4k it will have less torque and less HP thatn it does at a lower RPM.
A "M" moter is one of the most "choked down" or detuned that the big three ever built. Think Three parts: Induction (Intake and carb), Camshaft, and Exh.(headers) And free flowing duals.
choos the right combo and the engine will really wake up.

Sep 4, 2007 | 05:49 PM

likethefords

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From: Fargo, ND

The motor should be able to handle in excess of 3500 RPM, if you are unable to attain that, then I would suspect that you have a carb or timing issue. I had an 351M that would grab 6500 RPM, although I wouldn't recommend doing that a whole lot. I eventually blew it up.

Sep 4, 2007 | 06:02 PM

zpmps2

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Quote:

Originally Posted by likethefords

I had an 351M that would grab 6500 RPM, although I wouldn't recommend doing that a whole lot. I eventually blew it up.

LOL, 6500!!! Yep that would blow it up, my 351M i have the redline set "red tab" on the sunpro tack at 4500, but passing chebys i have had it to 5500 b/c i was looking over and laughing at em in 3rd and didnt notice it!! I only have it on 4500 b/c if anybody drives my truck i dont want them going to high, but i rarely get it over that b/c like the previous said, you lose torque. Hope this helps.

Taylor

Sep 4, 2007 | 07:50 PM

fmc400

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From: Austin, TX

These motors aren't meant to rev high and they won't put out much power at high RPMs. They were built to haul families around in big 70s passenger cars or they were put in medium-duty trucks.

Sep 4, 2007 | 09:11 PM

87f1504x42001

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the 79 im buying right now has 2 1/2 duals? i think lol. but it still has the stock manifolds, so how much power does the duals alone add?

Sep 7, 2007 | 10:57 PM

ErrorS

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I'd say something is wrong, my truck can spend all day at 4500-5000RPMS. I generally try to stay lower than that though, you can tell it just doesn't like the high RPMs.

The only time I really go that high is when I want to show off, whether it has any power or not these engines sound mean as hell at high RPMs.