1985 Corvette

Hey guys,

I found a small leak point on the D44 while under the Z today. It's not a rapid leak, just enough to make the collar around the driver side yoke look a little wet with a light on it. So looks like I found a way to blow my tax return in a few months. The car is only a weekend driver toy so it's not a huge priority right now but curious to know what a set of 3:75 gears would do. Who has made the switch? I was already considering this but now I have more of a reason to go through with it.

I have heard of Ikerd's and I checked them out for the full rebuild kits and gear sets. So I have a place to source the parts but curious also if there's a builder who could be trusted to put it together and not have to worry about it howling.

FASTAZU

ccmano

1985 Corvette

3:73 is what I meant, I think I had the existing 3:45s on the brain making the title and OP. I found a rather extensive discussion on the 4:10s vs 3:73s over on the registry forum.

http://www.zr1.net/forum/showthread.php?t=22970

Most likely old reading for the OGs around here but I'm having fun with it.

Rkreigh

the 4.10s work better in most situations. Once you start climbing over 600 at the tire a taller gear is needed to get much hope of any traction

I just went with 4.10s and bigger front and rear 18 tires make sure you stay within .75 front to rear diameters or you'll throw a traction control code

Phil got around this by machining a custom reluctor gear to run 345 tires in back which were probably 1 inch or so bigger than the fronts

enough to make the system unhappy

ZR1Bob

I agree with most--I went with 4.10s and they seemed perfect. Hard to see why Chevrolet did not make them optional like they used to do in the old days but I am sure it was emissions related. Did them on the '93 fairly soon after purchase and they were the first thing I did with the '95 along with a Corsa exhaust and a short shifter. Really improved around town driving and the only racing issue is that you need to shift into fourth at the drag strip. I thought about the 3.73s and researched it a bit but concluded 4.10s would be best. --Bob

Paul Workman

Yeah, with similar motor setups, the difference between 4.10s (yours) and my 3.45s in the 1/2-mile WANNAGOFAST side-by-side saw you cross the finish line first, but at 138 mph in 5th gear vs. 144.2x with my 3.45s still in 4th. Somewhere shortly past the 1/2 mile point the 3.45s would be favored, I recon - not that it matters so much to me. (Considering Pete's 391 package tho, and 3.45s might keep first gear relevant.)

5abivt

I Like 3.73s I think its perfect. I took out the 4.09s in my Lt1 car for 3.73s with 480rwhp and 8k rpm limiter the 3.73s were perfect and allowed 1st gear to be useful with an actual street tire that I could go high speeds and corner with too. 4.09s even with bolt ons on an LT1 got real tiring real fast. with the 388 stroker it was a joke. I don't like the ratios in the zf its like a 4 speed to me. I hate that 5th is pretty much an overdrive so I prefer stock gears. topping out 4th is fast enough and I can use 5th for top speed which isn't often. Plus longer gearing = less shifts at speed so for how I like to drive I prefer to shift less among other reasons

Dominic Sorresso

-=Jeff=-

I love the fun I have around town with the 4.10s. But my car is mostly stock

Faster5

ZWILDZR1

My first car was a 91 with Watson small primary tube headers, no cats, and a 3" early B&B exhaust, and a custom chip. It had the 4.10's and it ran great. I didn't have anything to compare it to as I hadn't driven a car with the 3.45's. At Bowling Green one year I was on the highway heading to the barbeque when I got into a little friendly competition with a stock geared car. I remember that we were dead even up to about 100 when I just started walking away until I let off around 150. My current car is 525 h.p. that Marc did and I think it will be better with a set of 4.10's.

cv67

3.73 isnt really enough that youll feel it or feel good about the money spent. 4.10 isnt as steep a gear as it sounds its just right.
Went from 3.08 on another car to 3.73 and regretted it...week later did the 4.10 and all was right.
If you got a car that redlines say under 6k then 4.10 isnt always best

Paul Workman

I'm still undecided. Switching back and forth between my 3.45 510chp and Ami's* 4.10s ~ 510 hp...its a LOT OF GEAR ROWING, especially in the mountain type twisty roads. It is great to run "The Dragon" in 2nd gear and let the rpm range of the LT5 handle the curves w/o having to row the gears (so much).

Of course, I'd like to have more torque throughout the rpm range. So, I guess its the old conundrum between gears and HP mods. 'The jury is still out'.

*Pete's cams, but smaller porting. Would be interesting to put it on a dyno someday out of curiosity.

Dominic Sorresso

Put 19"s on the back, then the 4.10s will work fine.

-=Jeff=-

Paul Workman

Oh, SUCHA novel idea! (NOT!)

-=Jeff=-

Dominic Sorresso

Rkreigh

LT5 layaway plan. Participating member.