How Fast does my 351M Turn?
Thread Starter
|
Laughing Gas
Joined: Aug 2004
Posts: 1,249
Likes: 2
From: Rockport, WA
How Fast does my 351M Turn?
I picked up a "$500 work truck" a while ago, a 1977 F250 with what should be a 351M -- at least that's what the VIN indicates; I haven't yet measured the stroke to see if anyone changed it to a 400. It came with an Edelbrock Performer 400 manifold and a terribly messed up Holley that I swapped for a new Edelbrock 600. It has dual exhaust, too, but no balance tube.
Assuming this is a stock '77 F250, no fancy cams or anything, what kind of rpm will I see in normal use?
I'm asking because I have been thinking of a tachometer. Most are sold with an 8,000 rpm range, which seems a waste of about half of that 270 degree sweep. I saw a 4,000 rpm tach advertised in J.C. Whitney. I'm thinking the 351M may occasionally top that (my 1996 454 Suburban shifts at 4,600 indicated when held to the floor).
Recommendations?
Thanks,
Lane
Assuming this is a stock '77 F250, no fancy cams or anything, what kind of rpm will I see in normal use?
I'm asking because I have been thinking of a tachometer. Most are sold with an 8,000 rpm range, which seems a waste of about half of that 270 degree sweep. I saw a 4,000 rpm tach advertised in J.C. Whitney. I'm thinking the 351M may occasionally top that (my 1996 454 Suburban shifts at 4,600 indicated when held to the floor).
Recommendations?
Thanks,
Lane
Elder User
Joined: Jan 2004
Posts: 867
Likes: 0
From: Eastern Pa
Get a tach that goes to 8000, that way if you miss a shift you can see how high it goes before it launches. A stock one might get to 5500 but I gotta think its wheezing that last 1000. Let it breathe a little with intake and headers and it'll get to 5500 but have a hard time with that stock cam.
Thread Starter
|
Laughing Gas
Joined: Aug 2004
Posts: 1,249
Likes: 2
From: Rockport, WA
That's good advice. My 351M is in front of a C6, so it won't be me that misses a shift -- unless it gets knocked into neutral, and stranger things have happened...
It sounds like my engine isn't likely to see 5,500 in it's present form, but it could turn well over 4,000. And the 8,000 tachometers are most common. I think I'll look for a small 8,000 rpm tach, maybe mount it and a voltmeter in pods on the A-pillar. My factory gauges work, but I want a voltmeter and I want to see how fast the engine is turning. I might even keep an eye open for a good vacuum gauge before I'm done.
Thanks for the help.
This is obviously the right place to ask.
Lane
It sounds like my engine isn't likely to see 5,500 in it's present form, but it could turn well over 4,000. And the 8,000 tachometers are most common. I think I'll look for a small 8,000 rpm tach, maybe mount it and a voltmeter in pods on the A-pillar. My factory gauges work, but I want a voltmeter and I want to see how fast the engine is turning. I might even keep an eye open for a good vacuum gauge before I'm done.
Thanks for the help.
This is obviously the right place to ask. Lane
