Siamesed TPI - 3.42 vs 3.73?
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Siamesed TPI - 3.42 vs 3.73?
I'm trying to decide which gear I should go with for my build, a 3.42 or 3.73. First, I'll throw out the specs of it:
350 TPI, siamesed aftermarket base and runners, looking to shift around 6k. Read up on siamesed TPI bases before telling me I shouldn't dare to shift nearly that high with a TPI
I'm also going with a TH350, full manual valve body. As I said before, looking to shift about 6k.
For the rear, I'm sticking with the stock GM 7.5" 10-bolt. Please hold the criticisms. It'll be mildly built, at least with an aftermarket differential cover.
Also should mention, I'm running 245/50/16 Nitto's.
Now I need to decide on a gear. I've heard many times that 3.73 is pushing the limits of the stock TPI powerband, and that 3.42 is an excellent choice. But, I'm not in the normal stock powerband. Also, the TH350 gearing will throw things off a bit compared to the 700R4.
I'm not at all concerned with gas mileage, this is a show/strip car. I'm looking for the best gear for a 1/4 ET, something that will put me decently in the powerband going across the line.
So, let's hear it, what do you guys think? What gear will best compliment my TH350 + raised TPI powerband?
350 TPI, siamesed aftermarket base and runners, looking to shift around 6k. Read up on siamesed TPI bases before telling me I shouldn't dare to shift nearly that high with a TPI
I'm also going with a TH350, full manual valve body. As I said before, looking to shift about 6k.
For the rear, I'm sticking with the stock GM 7.5" 10-bolt. Please hold the criticisms. It'll be mildly built, at least with an aftermarket differential cover.
Also should mention, I'm running 245/50/16 Nitto's.
Now I need to decide on a gear. I've heard many times that 3.73 is pushing the limits of the stock TPI powerband, and that 3.42 is an excellent choice. But, I'm not in the normal stock powerband. Also, the TH350 gearing will throw things off a bit compared to the 700R4.
I'm not at all concerned with gas mileage, this is a show/strip car. I'm looking for the best gear for a 1/4 ET, something that will put me decently in the powerband going across the line.
So, let's hear it, what do you guys think? What gear will best compliment my TH350 + raised TPI powerband?
Joined: Oct 2001
Posts: 12,228
Likes: 1,156
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: Siamesed TPI - 3.42 vs 3.73?
What cam and heads???
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
Ported 083's, and haven't quite decided on the cam yet. It'll be big duration for TPI though, maybe 224-228 int, 230 exh?
Joined: Jun 2004
Posts: 917
Likes: 31
From: Las Vegas
Car: '88 Trans Am
Engine: 5.7L TPI
Transmission: Slushbox
Axle/Gears: 3.27
Re: Siamesed TPI - 3.42 vs 3.73?
I would strongly suggest staying with 3.42s simply because you are still using a TPI intake they make tons of TQ down low and you have an automatic..... If you were a manual I would say 3.73s all day possibly 4.10s...
Try not to invest too much in gears and such at this point...
Try not to invest too much in gears and such at this point...
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
Do you think that'd put me in a spot in the powerband other than near the peak? Right now shifting my 305 at 5500 from first to second, I don't even make it into third by the end of the 1/4. I cross the line at about 5200 in second. I'd like to cross the line maybe 4800-5300 in third (with the TH350 opposed to the 700R4, like I said, skewing data). I'm worried that 3.42s won't be enough, and will put me across the line just into third, like my 700R4 does auto shifting.
Joined: Jun 2004
Posts: 917
Likes: 31
From: Las Vegas
Car: '88 Trans Am
Engine: 5.7L TPI
Transmission: Slushbox
Axle/Gears: 3.27
Re: Siamesed TPI - 3.42 vs 3.73?
With your set up you should consider staying with the 700r4 since the 1st gear being a 3.06 gear launches the TQ monster way harder..... A t350 would really want a 3000-3500 stall and 3.73 gears possibly even 4.10s to make it perform properly.....
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
Well the issue with that is my 700 already slips from first to second. I have to shift at 5200 for it to hit 5500. Also, I have the TH350 onhand, free and built up, so I'm sure it's understandable why I'd go that route. I also have the 9inch tailshaft, so install is fairly straightforward. So 3.42s are out of the question in your opinion?
Trending Topics
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
I should also point out, my goal is to hit 12s, and I'm prepared for buying a stall converter. I have been since day one lol. That raises my next question of what sort of a stall range should I be looking in? I see the range you've mentioned, but how would that vary between the two different rear gears you've mentioned?
Supreme Member
iTrader: (2)
Joined: Sep 2006
Posts: 2,118
Likes: 15
From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: Siamesed TPI - 3.42 vs 3.73?
TH350 is a 2.52 1st gear if memory serves me correct. That means that with a 3.73 axle, it gives you the same 1st gear as a 700R4 would with a 3.07 axle ratio.......With the 3.42's in there, you get the same ratio as a 700R4 with a 2.81 axle ratio. Either way it's pretty close.
At the same time, I wouldn't want to go any higher than 3.73 because your tach will be revving to the moon in 3rd gear.
Personally I'd run the 3.42's for the sake of highway driving, not to mention helping you get traction off the line. Then add a 3600 stall.
At the same time, I wouldn't want to go any higher than 3.73 because your tach will be revving to the moon in 3rd gear.
Personally I'd run the 3.42's for the sake of highway driving, not to mention helping you get traction off the line. Then add a 3600 stall.
Last edited by Reid Fleming; Sep 20, 2012 at 11:23 PM.
Supreme Member
iTrader: (2)
Joined: Sep 2006
Posts: 2,118
Likes: 15
From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: Siamesed TPI - 3.42 vs 3.73?
I went for a ride with esc last weekend. He has a TH400 with 3.31 axle and a 4200 stall. He has trouble getting traction in 1st gear. But he runs in the 11's with old stiff slicks. I'll see if he can chime in this thread.
I will say though, that his car is remarkably streetable with the stall. Take your foot off the brake and the car moves forward. With light throttle, you can do 1900-2100 RPM. Modest throttle and it will do 2500 RPM. More gas and it's in the 3000+ RPM range (and moving!)
I will say though, that his car is remarkably streetable with the stall. Take your foot off the brake and the car moves forward. With light throttle, you can do 1900-2100 RPM. Modest throttle and it will do 2500 RPM. More gas and it's in the 3000+ RPM range (and moving!)
Joined: Jun 2004
Posts: 917
Likes: 31
From: Las Vegas
Car: '88 Trans Am
Engine: 5.7L TPI
Transmission: Slushbox
Axle/Gears: 3.27
Re: Siamesed TPI - 3.42 vs 3.73?
Well the issue with that is my 700 already slips from first to second. I have to shift at 5200 for it to hit 5500. Also, I have the TH350 onhand, free and built up, so I'm sure it's understandable why I'd go that route. I also have the 9inch tailshaft, so install is fairly straightforward. So 3.42s are out of the question in your opinion?
Joined: Nov 2002
Posts: 2,007
Likes: 8
From: North of Houston
Car: '82 Camaro 11.7@121
Engine: 377
Transmission: 400
Axle/Gears: Dana 44 / 3.31:1
Re: Siamesed TPI - 3.42 vs 3.73?
PhoenixFirebird,
You said that this will be a track and show car, not a daily driver. In that case I would go for a stall that will get you AT LEAST to your max torque RPM. Anything lower and you will be wasting time, waiting for your power to arrive. A higher stall, somewhere between your max torque and max HP may make the car even faster...if you have traction.
I would probably go for the 3.73's and a 3200 -> 3500 (advertised) stall converter. I mentioned advertised because there are SO many factors that effect your true stall speed that it is almost impossible to know what you will get until you try it out.
One factor that often does not get enough attention is the torque multiplication effect of a torque converter. It acts a little bit like a "continuously variable" transmission in that it will give you a BIG torque increase at first, when it is slipping a lot. The torque multiplication factor depends on how the torque converter is made, but it can be (roughly) anywhere from 1.2 to 3. Good torque converter shops will build you a custom converter that will give you the torque multiplication you desire, allowing you to tailor your launch to your available traction. But even a "cheap" off the shelf 3500 converter will be a BIG help.
You said that this will be a track and show car, not a daily driver. In that case I would go for a stall that will get you AT LEAST to your max torque RPM. Anything lower and you will be wasting time, waiting for your power to arrive. A higher stall, somewhere between your max torque and max HP may make the car even faster...if you have traction.
I would probably go for the 3.73's and a 3200 -> 3500 (advertised) stall converter. I mentioned advertised because there are SO many factors that effect your true stall speed that it is almost impossible to know what you will get until you try it out.
One factor that often does not get enough attention is the torque multiplication effect of a torque converter. It acts a little bit like a "continuously variable" transmission in that it will give you a BIG torque increase at first, when it is slipping a lot. The torque multiplication factor depends on how the torque converter is made, but it can be (roughly) anywhere from 1.2 to 3. Good torque converter shops will build you a custom converter that will give you the torque multiplication you desire, allowing you to tailor your launch to your available traction. But even a "cheap" off the shelf 3500 converter will be a BIG help.
Last edited by esc; Sep 21, 2012 at 09:14 AM.
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
TH350 is a 2.52 1st gear if memory serves me correct. That means that with a 3.73 axle, it gives you the same 1st gear as a 700R4 would with a 3.07 axle ratio.......With the 3.42's in there, you get the same ratio as a 700R4 with a 2.81 axle ratio. Either way it's pretty close.
At the same time, I wouldn't want to go any higher than 3.73 because your tach will be revving to the moon in 3rd gear.
Personally I'd run the 3.42's for the sake of highway driving, not to mention helping you get traction off the line. Then add a 3600 stall.
At the same time, I wouldn't want to go any higher than 3.73 because your tach will be revving to the moon in 3rd gear.
Personally I'd run the 3.42's for the sake of highway driving, not to mention helping you get traction off the line. Then add a 3600 stall.
PhoenixFirebird,
You said that this will be a track and show car, not a daily driver. In that case I would go for a stall that will get you AT LEAST to your max torque RPM. Anything lower and you will be wasting time, waiting for your power to arrive. A higher stall, somewhere between your max torque and max HP may make the car even faster...if you have traction.
I would probably go for the 3.73's and a 3200 -> 3500 (advertised) stall converter. I mentioned advertised because there are SO many factors that effect your true stall speed that it is almost impossible to know what you will get until you try it out.
One factor that often does not get enough attention is the torque multiplication effect of a torque converter. It acts a little bit like a "continuously variable" transmission in that it will give you a BIG torque increase at first, when it is slipping a lot. The torque multiplication factor depends on the the how the torque converter is made, but it can be (roughly) anywhere from 1.2 to 3. Good torque converter shops will build you a custom converter that will give you the torque multiplication you desire, allowing you to tailor your launch to your available traction. But even a "cheap" off the shelf 3500 converter will be a BIG help.
You said that this will be a track and show car, not a daily driver. In that case I would go for a stall that will get you AT LEAST to your max torque RPM. Anything lower and you will be wasting time, waiting for your power to arrive. A higher stall, somewhere between your max torque and max HP may make the car even faster...if you have traction.
I would probably go for the 3.73's and a 3200 -> 3500 (advertised) stall converter. I mentioned advertised because there are SO many factors that effect your true stall speed that it is almost impossible to know what you will get until you try it out.
One factor that often does not get enough attention is the torque multiplication effect of a torque converter. It acts a little bit like a "continuously variable" transmission in that it will give you a BIG torque increase at first, when it is slipping a lot. The torque multiplication factor depends on the the how the torque converter is made, but it can be (roughly) anywhere from 1.2 to 3. Good torque converter shops will build you a custom converter that will give you the torque multiplication you desire, allowing you to tailor your launch to your available traction. But even a "cheap" off the shelf 3500 converter will be a BIG help.
Joined: Nov 2002
Posts: 2,007
Likes: 8
From: North of Houston
Car: '82 Camaro 11.7@121
Engine: 377
Transmission: 400
Axle/Gears: Dana 44 / 3.31:1
Re: Siamesed TPI - 3.42 vs 3.73?
I'm running some old hard Auto-X tires (Kuhmo V700 275-40-17, not a great drag tire) all the way around. During my last trip to the track, back in May, I had a best 60' of 1.96, with a lot of spin. I only ran 1/10 faster than my previous best in 2005, but I was 8 MPH faster. The difference is that in 2005 I hooked up and got a 1.7? 60'.
My point is that sometimes throwing more power at it doesn't always make it faster. Off the line traction is everything.
My point is that sometimes throwing more power at it doesn't always make it faster. Off the line traction is everything.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Siamesed TPI - 3.42 vs 3.73?
Agreed with esc. 3.73 and 3200 stall with th350 trans and let it eat! Will need sticky tires, nitto 555 drags may not be enough. Bfg or mickey should have a size in that range.
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
I planned on getting some MTs, but then I found this set of 4 Nitto's, basically free. Don't get me wrong, they have a decent amount of tread on them, but I figured they would be enough to get me through to next winter. Keep in mind I have a set of 4, and I'll only use them 2 at a time. So hopefully they last half a year a set lol. With my goal of 12.90s I'm a bit on the worried side, I must admit. At least I have a fairly heavy car still, it'll probably be about 3300 race weight. If anything, I'll try the Nitto's and see how well they do before I commit to buying MTs.
As far as the converter goes, do you have a price range for a custom built one from a shop? Unfortunately, I'll probably end up using an off the shelf one, as this is still fairly a budget build. I'm not looking for the cheapest converter around because especially with those, you get what you pay for, but I'm thinking around the $500 budget range for a converter.
As far as the converter goes, do you have a price range for a custom built one from a shop? Unfortunately, I'll probably end up using an off the shelf one, as this is still fairly a budget build. I'm not looking for the cheapest converter around because especially with those, you get what you pay for, but I'm thinking around the $500 budget range for a converter.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Siamesed TPI - 3.42 vs 3.73?
Lol heavy at 3300? My L98 car went 12.95 at 103.8 at 3450lbs with me in it and only bolt on mods with 2800 stall and 3.42's. If it was better tuned and had 3000-3200 it likely gone 12.7's.
If you got ported heads and intake mods you should have no trouble getting 12.9's but need as much of a launch as you can get. I was on et streets bias plys. 1.70 60 ft.
I ran an edge custom converter. 554 shipped back in late 2000's. Dont know the price now but bet its similar
If you got ported heads and intake mods you should have no trouble getting 12.9's but need as much of a launch as you can get. I was on et streets bias plys. 1.70 60 ft.
I ran an edge custom converter. 554 shipped back in late 2000's. Dont know the price now but bet its similar
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
You don't think I'll have a problem running 12.9? I've mentioned ported heads, but keep in mind they're 083s lol. At this point, should I invest in some weld on sfc's? I'm leaving the rest of the suspension alone, as it's the WS6 package, and that's my car number. If I did any suspension work it wouldn't be a WS6 package anymore lol. One thing that really distinguishes a Formula from a base bird.
Also, thanks Orr, I'll look into them. That's right around the price range I had in mind. As far as performance, what are your thoughts on it? How reliable has it been?
Also, thanks Orr, I'll look into them. That's right around the price range I had in mind. As far as performance, what are your thoughts on it? How reliable has it been?
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Siamesed TPI - 3.42 vs 3.73?
Love my edge converters. 2800 in the old iroc then restalled it to 3600 for my nitrous 383. I have a 3200 in my 99 trans am. Daily driver for 2 yrs and its been awesome.
I had stock heads on my car, 083's. 1.6 rockers on stock L98 cam. Hsr intake and gutted maf and air box with homemade ram air. Full exhaust, bolt on suspension
Mods stock irocz sway bars. Tokico adjustable shocks and eibach pro kit springs. Been that way since 03. Turbo car rides on same stuff. Car works.
Dont need much to get good times. Stock ws6 suspension will be fine. Just get good tires and converter
I had stock heads on my car, 083's. 1.6 rockers on stock L98 cam. Hsr intake and gutted maf and air box with homemade ram air. Full exhaust, bolt on suspension
Mods stock irocz sway bars. Tokico adjustable shocks and eibach pro kit springs. Been that way since 03. Turbo car rides on same stuff. Car works.
Dont need much to get good times. Stock ws6 suspension will be fine. Just get good tires and converter
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
Love my edge converters. 2800 in the old iroc then restalled it to 3600 for my nitrous 383. I have a 3200 in my 99 trans am. Daily driver for 2 yrs and its been awesome.
I had stock heads on my car, 083's. 1.6 rockers on stock L98 cam. Hsr intake and gutted maf and air box with homemade ram air. Full exhaust, bolt on suspension
Mods stock irocz sway bars. Tokico adjustable shocks and eibach pro kit springs. Been that way since 03. Turbo car rides on same stuff. Car works.
Dont need much to get good times. Stock ws6 suspension will be fine. Just get good tires and converter
I had stock heads on my car, 083's. 1.6 rockers on stock L98 cam. Hsr intake and gutted maf and air box with homemade ram air. Full exhaust, bolt on suspension
Mods stock irocz sway bars. Tokico adjustable shocks and eibach pro kit springs. Been that way since 03. Turbo car rides on same stuff. Car works.
Dont need much to get good times. Stock ws6 suspension will be fine. Just get good tires and converter
I really appreciate the input on this thread, it's knocked out two birds (lol, birds. No pun intended) with one stone. 3.73s + 3200 stall. Thanks everyone!
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Siamesed TPI - 3.42 vs 3.73?
Ohio is low altitude you should do fine. I had bone stock heads and springs just a rocker swap. Car ran hard
My buddys bolt on tpi car with siamesed runners ran 3.70 gears and it was a beast. Ran 13.5-13.6 in the heat with stock stall and street tires. My car ran 12.3-12.4's in that weather before rocker swap. And i was on slicks and stalled...But he did have a vette aluminum head motor in it but stock cam
My buddys bolt on tpi car with siamesed runners ran 3.70 gears and it was a beast. Ran 13.5-13.6 in the heat with stock stall and street tires. My car ran 12.3-12.4's in that weather before rocker swap. And i was on slicks and stalled...But he did have a vette aluminum head motor in it but stock cam
Supreme Member
iTrader: (2)
Joined: Sep 2006
Posts: 2,118
Likes: 15
From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: Siamesed TPI - 3.42 vs 3.73?
Just remember, with 245/50/16 tires on the car, your axle ratio will be your RPM at 70 mph. Depending on your exhaust, this can get quite annoying quickly.
3.42 = 3400 RPM
3.73 = 3700 RPM
Do TH350's have a lockup converter? Or are they unlocked all the time?
3.42 = 3400 RPM
3.73 = 3700 RPM
Do TH350's have a lockup converter? Or are they unlocked all the time?
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
Lockup versions of the TH350 are known as the TH350C.
Orr, you've got to stop posting these numbers. They're making me way too eager to do this swap, and I have to wait until April of 2013 to see what it runs. Back on the subject of Edge converters, perhaps you could elaborate a little bit for me.
http://www.edgeracingconverters.com/...18debbd3ecbb0e
I notice that the mild converter is rated up to 450HP, and for quite a bit cheaper than the $475 one I was initially going to take. I don't think I'm looking to make that much HP (right?), so would this be the best route to take? I know "you get what you pay for," but maybe the $220 price cut is worth the difference. Thoughts on this?
The TH350-C was the lockup torque converter version introduced in the late 1979 model year, and was produced through 1984. This later version had an electronic lock-up converter to increase fuel-efficiency at cruising speeds. The TH350-C lockup version can be indentified by an electrical plug on the left side of the transmission. When paired with an aftermarket TCC control unit, these can be desirable transmissions, and up to 10% more efficient at cruising speeds.
http://www.edgeracingconverters.com/...18debbd3ecbb0e
I notice that the mild converter is rated up to 450HP, and for quite a bit cheaper than the $475 one I was initially going to take. I don't think I'm looking to make that much HP (right?), so would this be the best route to take? I know "you get what you pay for," but maybe the $220 price cut is worth the difference. Thoughts on this?
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Siamesed TPI - 3.42 vs 3.73?
I dont think the mild edge can come in 3200 stall. This forces you into a street edge. That mild one is likely a 11-12 " comverter while street edge is 9-10". Makes it abit more efficient with higher stalls. Call edge and discuss. I was gonna do a 2400-2500 but they talked me into a 2800 and i am glad they did
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
Ahh, that's why I initially decided on the street. Then last night I looked again, and forgot about the stall limit on the mild. Thanks Orr, do you mind if I pm you about more questions on the build? They don't pertain to Transmission/Drivetrain, so I figured it'd be best to stop here.
Thread Starter
Senior Member
iTrader: (2)
Joined: Apr 2012
Posts: 604
Likes: 1
From: Norwalk, Ohio
Car: 1989 Firebird Formula
Engine: 385
Transmission: Full Manual TH350
Axle/Gears: Moser 9" 3.70
Re: Siamesed TPI - 3.42 vs 3.73?
Thread
Thread Starter
Forum
Replies
Last Post
hectre13
Engine/Drivetrain/Suspension Parts for Sale
2
Dec 11, 2023 08:14 AM
ambainb
Camaros for Sale
11
Apr 25, 2016 09:21 PM
Sanjay
Engine/Drivetrain/Suspension Parts for Sale
1
Aug 12, 2015 03:41 PM
