New rear end gears -

[olds307 and 403]

You are off by 100 ft/lbs on the 305's torque output. It only puts out 225 ft/lbs. That TH250C of mine lasted over 400,000 km behind an Olds 307. It had multiple fluid changes throughout its life. It might last awhile in good shape, it may not. I was probably around 350 ft/lbs.

 

[doood]

I had the local shop put this in for me:

GM75-PGBK-GM 7.5" & 7.625" 10 Bolt / Posi / Gears

www.quickperformance.com

Original gearing was 2.41 open. Now 3.55 posi. Love it.

 

[olds307 and 403]

I didn't realize 3.55 was available for a 7.5. It is a good in between ratio, especially with OD.

 

[ck1984]

I had the local shop put this in for me:

GM75-PGBK-GM 7.5" & 7.625" 10 Bolt / Posi / Gears

www.quickperformance.com

Original gearing was 2.41 open. Now 3.55 posi. Love it.

So what Hp/Tq is your crate engine running? and does that 3.55 posi hookup right away or can spin both tires?

 

[ck1984]

You are off by 100 ft/lbs on the 305's torque output. It only puts out 225 ft/lbs. That TH250C of mine lasted over 400,000 km behind an Olds 307. It had multiple fluid changes throughout its life. It might last awhile in good shape, it may not. I was probably around 350 ft/lbs.

oh sh*t , my bad, what ever site i used to look up Tq of 305 musta had the metric and imperial numbers swapped cuz i was surprised it had the same TQ

325 Nm / 240 ft-lb
	/ 1600
Horsepower gross:

 

[ck1984]

Other than the 88 model, H/O and 442, all Canadian models had the sbc and non CCC till 86. I believe there is a band vs an extra set of clutches. I killed one behind a 403, the first time out. The lock up converter prevents slippage on the "C" models.

excuse my ignorance but whats CCC?
do you happen to have any links to these 2004R trannys for sale cuz it doesnt search well in kijiji?

 

[olds307 and 403]

A computer controls the primary side of the carb. You may have to be patient for a 2004R. Are there any early 80's Olds Delta 88/98 till 1985, Buick Lesabre till 1985, Pontiac Paresienne till 86 or Chevy Caprice till 1988 big cars or full size rwd wagons till 90 in the local yard? I usually find one, when I needed.

 

[doood]

So what Hp/Tq is your crate engine running? and does that 3.55 posi hookup right away or can spin both tires?

It's a stock 5.3 gen 3 prolly 300hp at crank. It will chirp the 17x8 tires but it won't spin them - pretty consistent with the long debate about low-end torque missing in the case of stock tune. If I power brake, and smoke the tires, it tends to hop like it's going to tear itself apart. 1900 stall converter from 5.7L GTO, 4L60E, 2250 RPM @ 70 MPH with the 3.55 gears 26" tires, v6 springs. It goes; rear and trans appear tough enuf for stock LM7.

 

[ck1984]

It's a stock 5.3 gen 3 prolly 300hp at crank. It will chirp the 17x8 tires but it won't spin them - pretty consistent with the long debate about low-end torque missing in the case of stock tune. If I power brake, and smoke the tires, it tends to hop like it's going to tear itself apart. 1900 stall converter from 5.7L GTO, 4L60E, 2250 RPM @ 70 MPH with the 3.55 gears 26" tires, v6 springs. It goes; rear and trans appear tough enuf for stock LM7.

Do you have a link to that crate engine? a guy was just trying to buy my incomplete one and i was trying to tell him hes gonna spend at least 3000 cdn retrofittin it into his transam, he might be better off with a more complete used or crate engine.
Did you get the ratios changed in the 4L60?
some transmission expert on here said to multiply the 1st gear ratio x rear gear ratio and if you get over 9 you are in a high performance bracket, 10 or 11 and you can race for pink slips ;-)[im paraphrasing]
so if you got 3.06 1st gear X 3.55 posi=10.9 it should go like a bat out of hell?!
i have basically your same engine , well used, 2.29 rear X 2.52 1st gear =5.8.....it does NOT go like a bat out hell, least not off the line!

right now ive got a choice between some 3.08 gears i can strip out of an old complete rearend for 300 cdn
OR just buy some 3.73s and carrier for 150 cdn

im sure the 3.73s will be fun light to light but will have to put gerry cans of gas in the trunk to do any roadtrips, lol which will eat up the 150 dollars saved quite quickly
things that make you go Hmmmm?

 

[olds307 and 403]

It's a stock 5.3 gen 3 prolly 300hp at crank. It will chirp the 17x8 tires but it won't spin them - pretty consistent with the long debate about low-end torque missing in the case of stock tune. If I power brake, and smoke the tires, it tends to hop like it's going to tear itself apart. 1900 stall converter from 5.7L GTO, 4L60E, 2250 RPM @ 70 MPH with the 3.55 gears 26" tires, v6 springs. It goes; rear and trans appear tough enuf for stock LM7.

With the 3.55 gears it should roast the tires off the line. I could with a 8 to 1 Olds 350, 1900 stall 2004R and a 3.42 no slip rear. What diameter of tires are on it?