who was that question intended for? The best way to tell the rpm range with these motors is you can swap in a cluster with it for get an aftermarket. I just used an aftermarket. Its a bit difficult to tell exact RPM unless you have been driving this truck for years than you generally have an idea, especially if its a manual. But all in all your motor with rev to at least 4k. The thing i dont understand is are you just trying to make noise? If so cut off cat and muffler and add in a performance muffler with a direct exit pointing down or out the side. That will b plenty loud if not to loud.... People will hear you rev from 4 or 5 blocks away if you do it right.

 

No I'm not trying to make noise. I have a tach on my truck to know what imm taching. The reason I asked the question is to know what I could run thr motor up to because, I am about to drop a offy intake with efi headers and a 500cfm carb.

 

Unless your driving a manual or if you rev it in neutral there shouldn't be anything to worry about. If it is an auto it will only rev so high to begin with because it will auto shift. Unless you are in neutral. If it is a manual don't go past 4500 or you may start to run into problems. But since you are adding mods and going for performance its peak is at 2500-3500 from what i have experienced. So you should not shift at 4500 but more like 3500-3700 in my opinion to get the best torque curve.

 

Agreed. With both of my modded 300s (no internal work), this is just about perfect. I really only go to 4500 just to do it. It has plenty of power below, and 4500 is a good, safe ceiling.

 

With the stock 1bbl 3500rpm was the best I could do it was like hitting a brick wall when I got it there, and it sounded like it was going to blow up. With the 4bbl intake and carb it was nothing to rev it to 4500rpm, and it seemed like it would do more, but I know I shouldn't go over that without some internal modifications(valve stuff).

 

I know it's an old thread but for newcomers...

I'm shifting about 5100-5200 stock "88 efi bottom end except hv oil pump. C6 trans,18-20psi turbo. Holding strong so far. The 300 rod is strong, has been used in 460 strokers offset ground crank back in the day. Dual valve springs(for future cams) and Crower 284 hydraulic cam.

Going to the track Friday, will start a build thread with pics and video soon.

Dale

 

Fun Fact: If you can dig up old Ford saled literature with HP and Torque curves, they usually start at 1000 RPM on the TQ curve. The curves for the 300 extend past 1000 rpm down to 700 or so (idle).

My stock '88 EFI with a 3.55 rear and M5OD transmission will chug along at idle in 2nd gear (it idles pretty high at the moment). In fact, when I go over to the school to pick up my sun, I can just leave it in 2nd and brake to slow down when the buses are in front of me without it dying. It'll actually idle up when I let off the brakes.

I have feathered the clutch from a stop and gotten it to roll out at idle (true 600 or 700 rpm idle) without dying.

Typically, I run it in the 1500-2500 rpm range to try and maximize fuel economy. In fact, I really only run it up to 2500 rpm in 1st, because the 1-2 synchro is shot, so that's where it slots nicely into 2nd.

I rarely pull more than 3000-3500 rpm because there is no real need to. They few times I have even ventured that high were a time when I misjudged a car on the highway and needed to get going quickly and when towing about 6000 or so lbs and pulling onto a highway.

I would imagine that with some head work, a 500cfm carb and EFI heads should bring up the power band a bit. My EFI truck will spin from 2500 to almost 4000 pretty quick under full load, however it isn't much speed gain due to the 3.55 rear gearing. It's really happiest staying in the 1500-2100 rpm range.