[vortec72ss]

I have a 72 ss with a new 350, stock vortec heads, 212 in 222 ex @.050 cam, 9.6:1 comp, Edelbrock RPM intake, carter 625 carb, full length headers, 2.5 in. exhaust w/ flowmasters, and a th350.
The engine has been rated at 330 horse does this sound correct? My real problem is rear end gears. What should I be running? Right now i have the stock 2.73
gears and i know this is killing me. The car is a dailyu driver for now. I was thinking 3.55's or 3.73's?

 

[Wes Colby]

Vortec, the two gears you are considering are probably the best overall 'performance' gears for a daily 'street' driven car. If this car is going to serve as a primary daily driver for some time to come, then I would probably lean toward the 3.55's or even a 3.42 set-up.

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'70 Malibu - 383 'Fog Fed' Stroker! Gold Member #39
Chevellz Alwayz!

 

[vortec72ss]

Thanks Wes, much appreciated.
Could anyone out there possibly run my setup through a dyno and drag program. I tried to download one and had some problems. I'm curious as to my horsepower and my 1/4 mile time and speed. Please help out.

 

[Gene Chas]

Dragstrip plus rates the engine @ 308 gross HP. And you'd run a 15.87 w 2.73's ( stays in 2nd gear according to the simulation.)

I plugged in a 2500 stall converter ( assume you have stock 1800) and 3.73 ans you'd run a 13.90 w/same engine.

For whatever simulation software is worth.

 

[vortec72ss]

Gene, thanks for running that for me. Do you or anyone else think the 3.73 gears would have me revving too high while cruising at 60 to 65 mph?

 

[SirVette]

vortec72ss,

Consider changing your intake to Performer, instead of RPM. This will increase your low rpm HP (torque), & should not hurt high. You are probably shifting below 6000.
Your intake / gear combo. is killing your launch.
Then: how's your traction?
Probably the 3.42-3.55 Wes suggested is enough gear.
3.73 is no problem if you cruise at 60-65.

100+ is much better cruising speed for me.

 

[Harley]

Tire size (dia.) and converter stall info please.
Harley

 

[Gene Chas]

to ball park it, with my 4 sp ( no converter slip) 28" tires and 3.55's I run at 3000 @ 65 mph. 3.73's would bring that up to 3150. Not too much IMO.

now I'm not an auto guy anymore, but I would think you'd want your cruising speed to match or be greater than your converter stall or else heat will build quickly. Oh, and BTW, did I mention you need more stall to run a decent 1/4.

[This message has been edited by Gene Chas (edited 08-19-99).]

 

[L6571SS]

Gene is right with the 3.73's I have those in my 71 and at 65 its turnning around 3200. And about 4200 @90

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JT
71 SS Vortec 355
www.angelfire.com/co/KellyMotorsports