my 68 is a l36/390hp 4sp with an m21 and 3.08 gears..anyone else have this setup?

[Brandon T.]

Reason I ask is I was kinda let down when I ran the numbers and found that my car has 3.08 gears..

I did like finding out it had the m21 tho.

anyway, after a 3hr drive yesterday up through the mountains wow I really love this combo! the 427 offered PLENTY of torque to get you off the line and moving good and at highway speeds it's great! the thing actually does decent on mileage fora 427..haven't checked it but it seems to be pretty decent.

engine was pulled not long after I got the car and has recently been put back in so I just now really got to test it out on the highway etc..

My dad had a 66 years ago with a 4.11 in it and it was a blast but you couldn't take it anywhere hardly dc of the hwy drone and mileage, I remember him swapping that rear end out for something more tame not sure what it was 3.55 or taller probably but anyway was going to see if anyone else had a l36 with a m21 and 3.08's.

because from what I've read it's kinda rare to have a m21 with 3.08's..most with this ratio seemed to have had the m20. So, if you have this combo how do you like it?

btw..my car without winding it out barks going into 3rd pretty good! have even heard it in 4th I THINK but 3rd does it a lot with just mild driving. Ofcourse I only have 215x70's on it though.

anyway thought I'd see how u guys that have this combo like it.

[John M.]

Re: my 68 is a l36/390hp 4sp with an m21 and 3.08 gears..anyone else have this setup?

I had a 69 Chevelle 396/350 HP with the 3.08. It had the 375HP Heads with a .30 bore and was a Monster on the highway. It just kept pulling and pulling to the point I had to back down because of the suspension drifting which spooked me. It had a TH400 Automatic and barked in all 3 gears when you stomped it when the automatic shifted gears.

I just dropped my rear end from 3.70 with the M21 down to 3.55 in my 69 Vette.

Burning out of first gear with a high rear gear ratio is neat running stop light to stop light, but getting stomped at 65 MPH by a Honda Civic at highway speed isn't so cool when you run out of gear.

I personally like the 3.08 if you have a Big Block to pull you out of the low gears.

On the highway, it will be a machine to be dealt with in a 60-90 MPH burst when you drop it into 3rd and stomp it.

I like that set up and would leave it. It'll be a highway machine.

[Brandon T.]

Re: my 68 is a l36/390hp 4sp with an m21 and 3.08 gears..anyone else have this setup?

I had a 69 Chevelle 396/350 HP with the 3.08. It had the 375HP Heads with a .30 bore and was a Monster on the highway. It just kept pulling and pulling to the point I had to back down because of the suspension drifting which spooked me. It had a TH400 Automatic and barked in all 3 gears when you stomped it when the automatic shifted gears.

I just dropped my rear end from 3.70 with the M21 down to 3.55 in my 69 Vette.

Burning out of first gear with a high rear gear ratio is neat running stop light to stop light, but getting stomped at 65 MPH by a Honda Civic at highway speed isn't so cool when you run out of gear.

I personally like the 3.08 if you have a Big Block to pull you out of the low gears.

On the highway, it will be a machine to be dealt with in a 60-90 MPH burst when you drop it into 3rd and stomp it.

I like that set up and would leave it. It'll be a highway machine.

Yeah, shifting from 4th to 3rd at hwy speeds..nearly bring it to redline then shifting to 4th is infact a blast!

[Wayne M.]

Re: my 68 is a l36/390hp 4sp with an m21 and 3.08 gears..anyone else have this setup?

Brandon -- you should try close ratio and 3.08's with a SMALL block. My first car ever was a '65 L79 with this combo. (Protect-O-Plate dealer imprint below). I was 3rd owner in 1968 and the clutch was almost gone when I bought it. Didn't have a choice of M20 on the H/Perf engines in 1965.

Guess it could have been worse; a 30-30 cam on L76 or L84.

[Paul H.]

Re: my 68 is a l36/390hp 4sp with an m21 and 3.08 gears..anyone else have this setup?

My 68 L-36 has a 3:08 rear and a Turbo 400. To me it's the best of both worlds to have a big block that you can take on the highway. The 427 has plenty of low and mid range torque and with the 3:08 you can cruise on the highway and get near small block mileage, especially with those puny spreadbore primaries.

[Michael H.]

Re: my 68 is a l36/390hp 4sp with an m21 and 3.08 gears..anyone else have this setup?

Brandon -- you should try close ratio and 3.08's with a SMALL block. My first car ever was a '65 L79 with this combo. (Protect-O-Plate dealer imprint below). I was 3rd owner in 1968 and the clutch was almost gone when I bought it. Didn't have a choice of M20 on the H/Perf engines in 1965.

Guess it could have been worse; a 30-30 cam on L76 or L84.

The 64 L76/365 HP coupe that we bought new in early 64 had a close ratio and 3.08 rear. I hated it !! Worst combination ever for the street, as far as I'm concerned.