ok, I know that this is a lot to ask all at once but this stuff all works together and you guys are the experts so I feel I have a good opportunity here to nail the perfect combo right out of the box.

car in signature: 1970 chevelle
currently building the motor and rear end.

454 +0.030" 9.5:1
stock '049 heads
750 holley 4 barrel vacuum secondaries
full length headers 1-3/4" primaries, 3" collectors

th400 tranny - stock.

12 rear end - installing an eaton posi, still need to select gear ratio.

My intended use for the car is street only, but driven hard. I live no where near a track, but I would like to be able to make smaller road trips to car shows and perhaps one day a leg of the power tour, so I know that I do not want an overly aggressive rear gear.
I was thinking somewhere in the area of 3.55'ish or numerically lower.
One day I will swap in an overdrive 5 speed stick shift and perhaps reconsider the rear gear.

And finally I was just about to order the Magnaflow 2.5" stainless exhaust kit from Summit, but after reading some previous posts I'm starting to lean towards the 3.0" kit. I don't want to feel as though I am restricting the system with 2.5" but I am afraid that it might be a little loud at 3" they don’t offer a 3" head pipe with 2.5" tailpipe combo which I think would be the ideal.

Thanks in advance,

My best guess
1.Voodoo 276 cam
2. BTE 10' "tight" 3k conv.
3. 3.55 gears

my .02

dwhitf

ok,
I intentionally left the original post a little vague to try and draw out alot of opinions - but I think that I left it a little too open ended so I will firm up another detail.

I'm a little skeptical on running such a loe rear gear as I am used to my previous 2.73, but I have decded to definately run the 3.55 rear gear.

with the low gear I am thinking that 3k will be too much stall for me.

so lets hear what you guys think for a cam and convertor with the 3.55 gear, a th400 thans and preferably a stall <3k.

other specs.
9.5:1 454
stock '781 heads - 2.06 intake, 1.72 exhaust
750 holley 4 barrel vacuum secondaries
full length headers 1-3/4" primaries, 3" collectors

looking for a good all around driver with mix of street and highway driving.

thanks,

Since your used to 273 gear i would opt for 3;31's or 3:42s at most . Tihs is because your 454 will have plenty of grunt for that gear and compaired to 273 the 331 'sor 342's will make a big difference in seat of the pants feel and perf vs the 273.

Again since your used to 273's i would really consider the 331 or 342s. This is because the 3:55s will suck up a lot of fuel and generate more motor noise & heat when you dont need that much gear with all the cubes you have for a crusier and occassinal run down the strip. This is esp true for if you dont plan on a lot of strip racing even though the 331 or 342 gears would do fine for all but serious strip racing.

With 3:55s you will be turning approx 2900-3000 rpms (+ - 50-100 rpm depending on tire size) @ 60mph vs turing approx 2000-2100 rpms @ 60mph with the 372s,that approx 1000 rpms more which is a lot unless you have a small motor (which you dont)and do a lot of street crusing and strip racing which would require the extra gear.

Scott