Thanks thirdgen!
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Thanks thirdgen!
Just got my 85 on the road today.dropped a 30 over 350 in to the originally v6 car.my first build ever .i am mechanically inclined but never done anything like this with no help other than yall.and a buddy helped rip the old engine out.ive spent hours researching this site and it paid off.got a little more to do under the hood but runs drives great.thanks for all the help thirdgen
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
Pulling the v6
#3
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
After i got my 355 put back together
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
Engine in
#5
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
Today after my first drive..little snow on the ground
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
T5s holding up pretty well..gears till 3rd seem really short.clutch dost slip but I grinded rather than cut the input shaft unroll it fit nice an tight.got a lot of clean in up to do under the hood but I'm just stoked to have it on the road again
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
Ment to say clutch dosnt slip..but I ain't gonna dump it by no means you can till it's weak.havent had it dynoed but my set up is running around 360 75 .statistically. once I get outta second seems like I can get on it good ..advice would be great
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Car: '86 Camaro, '94 Camaro, 3 others
Engine: LG4 ->L29, L32->LR4, L36, LG4, L31
Transmission: 700R-4, T5WC, 4L80E, SM465, 4L60E
Axle/Gears: 3.42, 3.23, WTB/WTT 2.93
Re: Thanks thirdgen!
Third gear is one of the T5 weak links. Be gentle with third.
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
What do you think about 3.73s? In the rear?
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Car: '86 Camaro, '94 Camaro, 3 others
Engine: LG4 ->L29, L32->LR4, L36, LG4, L31
Transmission: 700R-4, T5WC, 4L80E, SM465, 4L60E
Axle/Gears: 3.42, 3.23, WTB/WTT 2.93
Re: Thanks thirdgen!
If both first AND second seem too much with a 3.42, then you would really hate a 3.73
I know it seems like everyone else chooses a 3.73, but that alone doesn't make it a good choice for you, and probably for a fair number of them, either.
For some of them, it's to get a certain cruise rpm without changing the transmission. For others, it is to get a desired rpm in their 1:1 transmission gear at the end of a 1/4 mile drag strip. And the rest are me-too, monkey see, monkey do. Don't be one of them.
I know it seems like everyone else chooses a 3.73, but that alone doesn't make it a good choice for you, and probably for a fair number of them, either.
For some of them, it's to get a certain cruise rpm without changing the transmission. For others, it is to get a desired rpm in their 1:1 transmission gear at the end of a 1/4 mile drag strip. And the rest are me-too, monkey see, monkey do. Don't be one of them.
Last edited by cosmick; 11-23-2016 at 03:47 PM.
#17
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
So second isn't quite as bad as first.but not great.3k rpm at 20_25 mph.so what would the 3.08 be like?
#18
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Re: Thanks thirdgen!
Brave man.
Kudos!
I want to do this someday when I grow up.
I need a garage so bad.
...and one of these
Kudos!
I want to do this someday when I grow up.
I need a garage so bad.
...and one of these
#19
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Re: Thanks thirdgen!
...although in my heart of hearts, I more need one of these one time in my life while I'm still on this side of it.
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Car: '86 Camaro, '94 Camaro, 3 others
Engine: LG4 ->L29, L32->LR4, L36, LG4, L31
Transmission: 700R-4, T5WC, 4L80E, SM465, 4L60E
Axle/Gears: 3.42, 3.23, WTB/WTT 2.93
Re: Thanks thirdgen!
Here's how to figure it out for yourself. First, you need to know the transmission ratios. For a V8-spec T5, they're 2.95/1.94/1.34/1.00/OD, either 0.73 or 0.63.
Then you need to know the effective diameter of your rear tires, which is 97% of their advertised diameter.
Now the math.
Trans ratio times axle ratio times 336 times mph, divided by effective diameter. That gives RPM.
First calculate what you already have to get a baseline. If it doesn't match what you observed, then either your speedometer is off, or your tach, or the axle ratio isn't what you thought.
But after playing with the math for 20 years, I gave up on most of it and started doing what most guys just do all along. Drive it as it is, if it seems too much then try a taller gear, if it seems too lazy try a shorter gear.
Finding a complete used 3.08 assembly is cheaper and easier than swapping 3.08 gears into an axle already fitted with 3.42s, then if you like how the 3.08s drive, add a limited slip to that. '90-up LO3/T5 came with 3.08:1 and 28-spline shafts. Older axles are only 26-spline. '85-up are 7.625" ring gears, pre-'85 were 7.50".
If you already have a limited slip and a 3.42:1, then you would need a different limited slip for the 3.08s.
If you adapted the v6-spec T5, then forget the axle and get the correct T5.
Then you need to know the effective diameter of your rear tires, which is 97% of their advertised diameter.
Now the math.
Trans ratio times axle ratio times 336 times mph, divided by effective diameter. That gives RPM.
First calculate what you already have to get a baseline. If it doesn't match what you observed, then either your speedometer is off, or your tach, or the axle ratio isn't what you thought.
But after playing with the math for 20 years, I gave up on most of it and started doing what most guys just do all along. Drive it as it is, if it seems too much then try a taller gear, if it seems too lazy try a shorter gear.
Finding a complete used 3.08 assembly is cheaper and easier than swapping 3.08 gears into an axle already fitted with 3.42s, then if you like how the 3.08s drive, add a limited slip to that. '90-up LO3/T5 came with 3.08:1 and 28-spline shafts. Older axles are only 26-spline. '85-up are 7.625" ring gears, pre-'85 were 7.50".
If you already have a limited slip and a 3.42:1, then you would need a different limited slip for the 3.08s.
If you adapted the v6-spec T5, then forget the axle and get the correct T5.
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Car: 85 firebird 350 .30 over 650 Holly.
Engine: 355.rollers.650 Holley. Thumper.cam
Transmission: V6 14 spine t5 .wouldn't recommend
Axle/Gears: 3:43 ls gotta be changed
Re: Thanks thirdgen!
I haven't had the car dynoed.im only able to look at it from a statistical standpoint for my set up of the engine right now.so I would feel very safe to say around 350- 60 hp harder to figure out torque just to many variables