I'm running a comp cam 280H in my SB 350 and I would like some suck your eyes to the back of your head low end, without sacrificing mid or top. I also have Edelbrock preformer RPM intake, Holley 650(would a 750 work?), the heads,(I was told by the guy who sold the car to me),are 194 valves,(don't know if that means anything,I'm just starting out working on cars).

A gear change would put you back in the seat. What do you have now?

Pat,
Interesting you should ask that, I was going to offer the same comment. Going to do another of those way back when things, but, years ago, it was common to run 4.10's, even 4.56's on the street. And that was with big blocks as well as small blocks. The way we always looked at it was a motor that would turn 6000 was a good match to a 4.10; 6500 go with 4.33's or even 4.56's. I am surprised at how high the gear ratios are on the street cars today (talking weekenders and cruise night cars). From a performance standpoint, there is a lot left on the table with out big gears.

I have a 12 bolt 3.73 rear in the car. I've actually wanted to put in 4.10's, but I have a th-350 and I'm already pushing 3000-3200 rpm to do about 60-65 mph or so,(my speedo doesn't read right, the gear in the tranny was never changed.).
Would 4.10's have a dramtic affect on highway driving? I do like to go out for a cruising on a nice day.

Drop back to the good old CC 270 Magnum or 270S solid if you want that thing you are looking for b/c if you don't have at least 10.25, (and better a true 11), to 1 CR. with the 280 Magnum, you are leaving a bunch of power on the table..

pdq67

I'm not to sure what the compression is, I do know the motor has TRW pistons. Can I do a basic compression test on the motor to see the true compression or is it more complicated than that? I'm new to the hot rod stuff so I don't know. If the compression is under 10.1 is the power being lost dramatic?

Please don't take this the wrong way..
Maybe you're car needs some tuning.What's your timing curve? Do you have a stall convertor?
3.73's is all you'll need IMHO.Most often than not,gear swaps are a poor substitue for maximizing a combo,especially in street car that doesn't see track time.It just takes some patience to get it right.

3.73 gears are plenty. If the engine has stock 76cc heads, and I've seen a lot of engine with these heads and 280 cams, then that is a big part of the problem. The compression ratio is way too low, probably under 9:1. A 280 cam would want, at the least, 10:1 to 10.2:1. If you want to stay with the cam, putting 64cc heads on would make the engine much stronger. With 76cc heads, way too much of what little compression you have is being bled off. If you stay with 76cc heads a very short cam is needed, which may not match up with the gears you have. I think the first thing to do is pull the valve covers and get the casting numbers. Post them here so we can know, more or less, what you have.

Another issue is the converter. A higher stall is needed with a 280 cam. Too low of a stall will keep the engine out of the power band at low rpm. Have you noticed if the engine is rather doggy until it reaches a certain rpm? Too low of a converter stall will do this.

I think going to 64cc heads (preferably aftermarket, if the current ones are 76cc), and putting in a 2200-2400 rpm converter will help immensely.

Thx Pat for the back up AND I didn't run it through your great program either..

I still think a 270S magnum solid cam would do fine for him..

pdq67