Advice on plan B
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Teching In
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Advice on plan B Well everybody its winter time here and im planning ahead for summer. Im almost done my SBC to LS swap in my 62 gmc and im looking for advice.
The engine is a 5.3 with a s476 and a turbo cam and the goal with enough boost and meth is 800hp to start.
I bolted it up to my 700R4 that was behind the previously supercharged SBC. I was told by the company that supplied the parts for the tranny that it will only hold ~600hp. The truck will be street driven with weekend drag racing.
Currently in my garage i have both a Glide and a TH-400 that i could build up in the event that i scatter the 700R4.
My question is....What should i build for a plan "B" tranny?
The engine is a 5.3 with a s476 and a turbo cam and the goal with enough boost and meth is 800hp to start.
I bolted it up to my 700R4 that was behind the previously supercharged SBC. I was told by the company that supplied the parts for the tranny that it will only hold ~600hp. The truck will be street driven with weekend drag racing.
Currently in my garage i have both a Glide and a TH-400 that i could build up in the event that i scatter the 700R4.
My question is....What should i build for a plan "B" tranny?
TECH Junkie
Joined: May 2012
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From: Poplarville, MS
Is your engine carbureted or are you using a PCM to control fuel injection? If you are using a PCM I would use a 4L80E and use the PMC to control it. The 4L80E would be great for street use and hold up to your HP goals. If carbureted the TH-400 would be better for the street use over the Power Glide and will also hold up to your HP goals. I think your truck will be a little heavy for the Power Glide to hold up, this is just my opinion on the Power Glide.
Thread Starter
Teching In
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Is your engine carbureted or are you using a PCM to control fuel injection? If you are using a PCM I would use a 4L80E and use the PMC to control it. The 4L80E would be great for street use and hold up to your HP goals. If carbureted the TH-400 would be better for the street use over the Power Glide and will also hold up to your HP goals. I think your truck will be a little heavy for the Power Glide to hold up, this is just my opinion on the Power Glide.
TECH Junkie
Joined: May 2012
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From: Poplarville, MS
If street driven I would prefer an overdrive trans like the 4L80E, the 700R4 will not hold up to your HP goals. But I don’t think your Holley HP has the ability to control the operation of this trans, so you will need some type of stand along controller to get it to work. If money is an issue and it almost always is and you don’t mind not having an overdrive run the TH 400.
The Power Glide is not a very good street trans and I don’t think it would work very well in your heavy truck.
The Power Glide is not a very good street trans and I don’t think it would work very well in your heavy truck.
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From: Ann Arbor, MI
^^^ Exactly agree.
4L80E are readily available at junkyards for under $300.
Great current thread of 4L80E versus TH400: https://ls1tech.com/forums/automatic...400-4l80e.html
IIRC the Holley HP controller does not control a trans, but the Holley Dominator EFI does.
4L80E are readily available at junkyards for under $300.
Great current thread of 4L80E versus TH400: https://ls1tech.com/forums/automatic...400-4l80e.html
IIRC the Holley HP controller does not control a trans, but the Holley Dominator EFI does.
Thread Starter
Teching In
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Yes im starting to lean towards the TH400 for the time being. I did get in contact with the company who supplied all the parts for my 700R4 and they basically told me if I change the input shaft and shell then it should hold 1000 ft/lbs. They sell a transmission with similar components with that rating. Although a more modern 4L80 seems very appetizing. I weighed the truck a couple months ago with the old SBC and weiand 177... it came in at 3973 with out me in it
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From: Ann Arbor, MI
A 700R4 uses the same internal parts as a 4L60E and neither trans can hold 1000 ft/lbs; certainly not for any extended time. I built my 4L65E with all the upgraded and billet parts available which puts it's cost at $5000+ (similar to what e.g. FLT sells their Level 7 with billet options), yet if I ever go past 700 ft/lbs or 750 HP, I will switch to a 4L80E.
A modestly built TH400 or 4L80E can certainly handle such power levels.
Somewhere around 600HP, unless you have a C5 Vette or other reason where you must use a 4L60E, it becomes cheaper to upgrade to a 4L80E.
A modestly built TH400 or 4L80E can certainly handle such power levels.
Somewhere around 600HP, unless you have a C5 Vette or other reason where you must use a 4L60E, it becomes cheaper to upgrade to a 4L80E.
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Teching In
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A 700R4 uses the same internal parts as a 4L60E and neither trans can hold 1000 ft/lbs; certainly not for any extended time. I built my 4L65E with all the upgraded and billet parts available which puts it's cost at $5000+ (similar to what e.g. FLT sells their Level 7 with billet options), yet if I ever go past 700 ft/lbs or 750 HP, I will switch to a 4L80E.
A modestly built TH400 or 4L80E can certainly handle such power levels.
Somewhere around 600HP, unless you have a C5 Vette or other reason where you must use a 4L60E, it becomes cheaper to upgrade to a 4L80E.
A modestly built TH400 or 4L80E can certainly handle such power levels.
Somewhere around 600HP, unless you have a C5 Vette or other reason where you must use a 4L60E, it becomes cheaper to upgrade to a 4L80E.
TECH Junkie
Joined: May 2012
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From: Poplarville, MS
Nothing wrong with the TH400 you would just get lower engine RPM and better fuel mileage cursing around with the 4L80E. The TH400 was all we old time hot rodders had back in the old days.
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From: Ann Arbor, MI
If considering a 4L80E, I've read many posts where people buy them from their local junk yard for $300 or less. Truck gas or diesel, mobile home, they are all basically the same. I would aim for a '98 or later, but in some ways the earlier ones are stronger.
With a few harness mods, the PCM controlling your LS1 can control the 4L80E.
I suspect your '62 GMC will have plenty of room for the 4L80E without serious mods.
I don't know if a stock TH400 is stronger than a stock 4L80E, but I suspect they are similar (other than the OD) and the lower mileage unit would have advantages.
With a few harness mods, the PCM controlling your LS1 can control the 4L80E.
I suspect your '62 GMC will have plenty of room for the 4L80E without serious mods.
I don't know if a stock TH400 is stronger than a stock 4L80E, but I suspect they are similar (other than the OD) and the lower mileage unit would have advantages.