What are you trying to accomplish with the 3.73?
Id say stick with the 3.08 behind an olds. My dying 350 skylark had 2.73 in the back. It would roast the tires all day long. In my opinion, you lose more on the street than you gain at the strip when stepping up the gear in an olds. You have the low end torque that the chevy guys dont, so youre not going to gain as much as you think.
A freind's 69 cutlass had a high compression hi performance olds 350 with 3.73 (we thought it was 4.11). The car was plagued with overheating, and hot start issues all its life. If you have been battling cooling issues, it will get MUCH worse, there are ways to fix this though.
With the 3.73, TH350, and 245/60/14 tires (~26ish tall), the car would cruise and shift into third around 40km/h (I think thats 25mph). 1st gear was completely useless for daily driving. From there it would rev all the way up to 3200ish for cruising on the highway. It felt like the engine was labouring/surging. He went from the 650cfm carb to a 750cfm carb, and it was happier but the overheating was still there. As a result he never drove over 50mph.
When he went to 3.08's the seat of the pants was different, but only the initial "jolt" off the line. It didnt feel too different everywhere else, and was still scary fast. Just now he could drive everywhere.
If you want the 3.73 to gain at the track, at the expense of some street driving, it will gain something. Heres how you fix the cooling issue. He went to a Griffin aluminum radiator, a Summit Brand highflow waterpump, Derale Dual Electric Fans, and Derale programmable fan controllers. With 160*F Thermostat, he cant get the car up to temperature. So he will be putting in a 185* in the summer. The only crappy thing about this, is you will also have to buy the fairly expensive pulley for this waterpump, as the snout length is quite different.
Id say stick with the 3.08 behind an olds. My dying 350 skylark had 2.73 in the back. It would roast the tires all day long. In my opinion, you lose more on the street than you gain at the strip when stepping up the gear in an olds. You have the low end torque that the chevy guys dont, so youre not going to gain as much as you think.
A freind's 69 cutlass had a high compression hi performance olds 350 with 3.73 (we thought it was 4.11). The car was plagued with overheating, and hot start issues all its life. If you have been battling cooling issues, it will get MUCH worse, there are ways to fix this though.
With the 3.73, TH350, and 245/60/14 tires (~26ish tall), the car would cruise and shift into third around 40km/h (I think thats 25mph). 1st gear was completely useless for daily driving. From there it would rev all the way up to 3200ish for cruising on the highway. It felt like the engine was labouring/surging. He went from the 650cfm carb to a 750cfm carb, and it was happier but the overheating was still there. As a result he never drove over 50mph.
When he went to 3.08's the seat of the pants was different, but only the initial "jolt" off the line. It didnt feel too different everywhere else, and was still scary fast. Just now he could drive everywhere.
If you want the 3.73 to gain at the track, at the expense of some street driving, it will gain something. Heres how you fix the cooling issue. He went to a Griffin aluminum radiator, a Summit Brand highflow waterpump, Derale Dual Electric Fans, and Derale programmable fan controllers. With 160*F Thermostat, he cant get the car up to temperature. So he will be putting in a 185* in the summer. The only crappy thing about this, is you will also have to buy the fairly expensive pulley for this waterpump, as the snout length is quite different.
