vettefast

Well the engine has been done since July and is running great! Now I want to change the gears. It currently has the 3.07 stock performance gears and I was wondering how high I can go before I am not streetable. I currently have between 430-450 hp. It is not a daily driver. It is for weekend and summer fun. I was thinking 3.73s? Thanks!!!

FELNGR8

Even the drag racers limit themelves to 3.73 with an auto. The 6 speed can handle 4.10 and be roadable, but that's too much for the auto.

You will get an argument from plenty here that 3.73 is too steep for a torquey 383 engine. I won't get into that.

65Z01

For best results at the strip you should try to use all of your 1:1 tranny ratio close to the traps.

So, from your shift points and tranny ratios you can come with optimum gears for 1/4 mile performance.

88BlackZ-51

What was done to your 383?


430-450 chp is real good.....

Matt383

I use 3:73 gears on my stroker.
Very happy with them.

See sig.

Matt383

vettefast

Engine parts in this engine include the following:

A race prepared block with silverstone steel 4 bolt caps, ARP main studs, parrallel decked to 9.00" bored and torque plate honed to 4.030", clearanced for stroker, Durabond cam bearings and pioneer brass freeze plugs installed.

EnginePro rotating assembly whit a scat crackshaft 3.750" stroke, Scat I-Beam connecting rods 5.700", Speed-Pro coated hypereutectic pistons, Clevite rod and main bearings and JE piston rings.

Cloyes true timing set.

Crane Compucam roller camshaft

Melling roller lifters

Fel-Pro gaskets

Melling oil pump, screen and heavy duty oil pump shaft.

Pro Topline 200cc Aluminum cylinder heads with a competition valvejob and resurface. Heads were assembled with Manley stainless steel valves, springs, spring cups, retainers, locks, studs,guideplates, pushrods and head bolts. Enginetech valve seals.

Comp Cams roller tip rocker arms and Mr. Gasket poly locks.

Pioneer heavy-duty flexplate.

Carter water pump.

GM oil pan, oil pan rails, cam plate and bolts, lifter retainers and plate, timing cover.

Accel Street Ram Manifold, runners and plenum.

Fram oil filter

Rotating assembly computer balanced.

Cam degreed and piston rings file kit

Ford SVT 24 lbs fuel injectors.

Engine balanced and assembled.

vettefast

Are you having any problems spinning from a start??? I have Nitto drag radials 315/35/17 in the rear.

Matt383

I know this sounds
But I have 14 wheels and tires for my car.
Different wheels and tires for diffrent applications.
It is hard to find a tire that does everything (drag, cornering, wet, etc.)
For DOT only races I use BFG Drag radials... same size as your Nitto's.
I have heard that Nitto's don't hook as well as BFG's but I have never owned a set of Nitto's. BFG's hook real well when I run motor only.
I smoke the hides off 'em when I launch with Nitrous.
The only thing that hooks for me when I turn in 1.52 sec 60 ft times (with N2O) are Hoosier slicks on 15" wheels.
(I get 1.68 times with BFG's)
Hope this helps.

Matt383

85vet

I went with 3:54's with my setup and it puts me through the 1/4 mile trap at 5800 to 6000. With the 4000 convertor and the new gears the car responds instantly. With the 3:07's there was a delay when starting out on the street and it is definately gone.

I run Hoosiers 15" and when the track is preped properly I can hook nice.

88421VETTE

3.54's all the way

J Z06

For the L98 and a 383, a lot are going to say 3.07's are fine. I liked the 3.45's in my former LPE-383 VERY much. They made cruising fun and weren't bad at all on the highway(65mph@2200 I think).

J Z06

understatement! that thing is a rocket!!!!

85vet

Shhhh!! I like to be low keyed, Jeese I am almost stock

J Z06

stock

vettefast

Ok....What would the down falls of me putting in 3.73 over say the 3.45s or the 3.54s???

vsocks

What rims are you guys using for the Hoosier 15" tires?

vettefast

What I really like to know is there anyone who has put 3.73 on there vette with over 400 hp and regret it while driving on the street???

85vet

weld prostar Jegs#927-96-58280 15X8 5.5RS 4.75BC

Matt383

Same for me.

Also, the more I think about it. I may weigh the option of going to a 3:54 next time I need gears. which is more often than I would like.
Reason is that I have a T400 trans...three gears.
I may pick up on the top end and some ET as I go through the traps at 6500 rpm or more now.

Matt383

85vet

Matt383,
If you are going through the traps at 6500 now - if you go with 3:54's you will get to 6500 before the traps and be at your rev limiter 7000+(if you have one through the traps) unless of course your motor is setup to rev at 7000+.
I picked up about 500-600rpm's through the traps with the 3:54 gear change.

Just my thoughts on the subject.