I had posted yesterday about having an open 10 bolt and looking at different rears And what what fit my 67 Chevelle.
My next question is...how important is a posi rear? I’m doing a frame off restomod and already have about 7k in parts in it and still have 25k or so of parts priced out and left to buy on my build. I know some of you will think we’ll 30k, what does another 2-3k matter?
I just want to make sure it will be absolutely worth it before I add another 2-3k to my build.
I figured I’d add that I’m building my car to cruise around and occasionally get on it but not a drag or racing car by any means. Newer engine, TR6060 6 speed...around 500hp at the motor. I want to be able to efficiently cruise at 60mph but also if the urge arises I would like to be able to get up and go. Want to make sure I have the right rear.
So with that being said, is not having a posi really going to be a big deal if I’m not out ripping it and trying to do burnouts? Is it something I could get by without having right away?
Also if a posi is a MUST have, which gears should I get for what I want to use the car? Doing research I was thinking more like 4.10 or 3.73
I don’t know much about rears and gears which is why I’m asking. Thanks for the help! You guys are the best.
It depends on how fast you intend to let out the clutch when you "get up and go". If you don't intend to smoke the tire(s), and just step on the gas after the car is moving (mostly in 2nd gear, or higher?), posi is optional. AND, it can always be added later if you feel the need. You state "...I'm not out ripping it and trying to do burnouts..." .
A nice mid range rear (around 3.55?) is where I would focus as I understand your needs.
Wanna save a few bucks? Again, as I understand your needs, I'd back off the 500 hp. I'd focus on low end torque; perhaps a sbc that produced a minimum of 420 lb-ft of torque (at approx 3500 rpm). I would not care what the hp rating was. It would 'fall out' from the following equation:
hp = (torque x rpm)/5252
(ever wonder why ALL hp/torque curves 'cross' at 5252? That's why)
So, at 3500 rpm and 420 lb-ft of torque, hp (at that rpm only) = 280 hp.
As rpm rose above 3500 the torque would drop off some from the max. How much, depends on the 'build' of the engine. I (just me) would not care what hp was at a typical red line of about 5200 rpm. IF the torque dropped to 380 lb-ft at 5200 rpm; hp = 376.
That should be enough for your stated needs (as I understand them). It's a simple, easy, reliable build. A sbc 383 perhaps?
Just some ideas for your consideration.