4spd or th400 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

manimal · 11-02-2006, 03:23 PM

I am getting ready to start the build-up of a 496 stroker BBC to put in my 1 ton 4x4.It currently has a SM465 trans and a NP205 transfer case.My question is will this 4 spd handle this kind of engine or should I swap in the th400?

1969 GMC · 11-02-2006, 09:18 PM

it will handle that no problem, just make sure you have a good clutch.

Hoods69BadBowTie · 11-03-2006, 02:44 AM

Ya, with a good clutch it should be able to handle it no problem.

vtblazer · 11-03-2006, 04:26 AM

I agree, the 4spd will handle it, no doubt.

My question would be, do you really want it?
A 4spd tranny isn't the best choice for hard wheeling IMO.

What's the purpose for the build?
Mall cruiser or actual wheeling?
What tire size/gears are you ending up with? Lift?
What axles are you running? Any other mods?

manimal · 11-03-2006, 09:46 AM

No I'm not going to be rock crawling, but I do plan on playing inthe mud,going camping with the family,playing in the snow,and alot of towing.
The axles that I have a re a dana 60f with 4.56 and a 14 bolt ff in the rear with the same gears. Right now I am running BFG mud terrains 35x12.50x16.5. I do have a built TH400 but its 2wd. So I called Advanced Adapters,and they have an adapter and input shaft to use the 2wd trans for about $600.
So maybe I'll go that way.

gator2511 · 11-03-2006, 06:42 PM

Quote:

Originally Posted by manimal

No I'm not going to be rock crawling, but I do plan on playing inthe mud,going camping with the family,playing in the snow,and alot of towing.
The axles that I have a re a dana 60f with 4.56 and a 14 bolt ff in the rear with the same gears. Right now I am running BFG mud terrains 35x12.50x16.5. I do have a built TH400 but its 2wd. So I called Advanced Adapters,and they have an adapter and input shaft to use the 2wd trans for about $600.
So maybe I'll go that way.

Thats the exact way I went with my 72K10. You will have to bore out the input shaft bearing opening in the np205 for the new bigger shaft and bearing.

**kwmech** · 11-06-2006, 10:19 PM

If/when you get to that point I have the adaptor and the t-case----all rebuilt

manimal · 11-07-2006, 09:56 AM

Great I'll keep that in mind

**Zoomad75** · 11-09-2006, 12:55 PM

Quote:

Originally Posted by vtblazer

My question would be, do you really want it?
A 4spd tranny isn't the best choice for hard wheeling IMO.

Isn't it? I guess it's all a matter of opinion, but I love having a 465 in my K5. No automatic can crawl or compression brake like a 465 in Granny.

They each have their place and lots of guys are hunting to find a 465 to swap in for an auto. Still it takes a little finnese to wheel using both feet and both hands. I just like having that type of control. Plus if I'm crawling up a rocky trail, I end up picking a gear and leaving it there. Same going down hill, depending on how steep it is I'll go to granny or 1st and leave it there and creep down rarely touching the brakes.

An Auto can do better in the mud where wheel speed and quick shifts are needed. But for trail riding I'll keep my 465.

It's up to you, But I doubt you would blow a 465 up. Just get a decent clutch like others have said.

manimal · 11-09-2006, 05:29 PM

Yeah I have been talking to some friends and they say the same thing,so I think I might keep my 465/205. I will probably run a centrforce dual friction clutch. THANKS EVERYBODY!

Bad71chev406sbc · 11-10-2006, 02:07 AM

yup....the 465s are pretty much bullet proof. A good clutch is an absolute must....stg 2 or 3 centerforce. I've got a friend that's swapping in a 465/205 instead of his th400/205....he's blown up about 14 of these. I guess th400s can't handle 44's and 400hp. It actually cracks the cases straight in half in the middle.

vtblazer · 11-10-2006, 07:25 AM

Quote:

Originally Posted by Zoomad75

Isn't it? I guess it's all a matter of opinion, but I love having a 465 in my K5. No automatic can crawl or compression brake like a 465 in Granny.

Glad you love your 465.

when built correctly, an auto tranny 'can' and 'does' crawl and compression brake every bit as well as a standard transmission without the need for that third pedal.

WAY better in the rocks while crawling.
An auto will allow for more finesse with better control on the steeps too.

manimal · 11-10-2006, 03:09 PM

the only time I have ever cracked a case is when the slip yoke was worn out and caused the driveshaft to vibrate in my 76 k20

**Zoomad75** · 11-10-2006, 03:50 PM

I think we are going to have to agree to disagree. I'll admit with enough money put into any part, it should perform better than stock. But, while my 465 is stone stock you have to put $$$$ into any auto (th350 or 400) to make it work like the stock 465 does. Converter's and full manual valvebodies cost money as does the labor of some auto trans tech to put it together. Sure you can re-gear an auto with a lower ratio panetary set for added low range, but those gearsets are not cheap either.

Sure a fully preped auto can crawl. Heck most of the pro rock crawlers are using Powerglides for that matter. But as far as Joe Schmoe weekend warrior goes, you can't beat the bang for the buck a 465 gives with all it's stoutness and versitility.

And as far as fineese on the rocks and crawling are concerned, I do just fine. Last trail I ran had large section of rocks with a steep rocky climb out of a river bed. 4lo, Granny, picked my line and idled over it. Both hands on the wheel and my left foot resting on the floor. coming down I did the same thing. never touched the brakes or the clutch.

Can't overheat my 465 either....

vtblazer · 11-10-2006, 06:36 PM

Well said Zoomad75.

I concur.

Couple things I didn't disclose earlier.
1st - I'm running a doubler with 5:13 gears which gives me better than 100 to 1 ratio when in low/1st.

2nd - my th-400 was rebuilt for only 1K using off the shelf parts along with another 2wd tranny I already had. (spraggs came from the 2wd)
They added an extra clutch plate and worked it so it has the compression braking of a standard.
Pretty basic build in reality.

If your out Wheeling, it's all good.

**Zoomad75** · 11-10-2006, 07:10 PM

Well, adding another 2:1 reduction into the drivetrain, would have a big impact on cawling as would 5.13's, plus the torque multiplcation of the converter itself.

I'm lucky, my K5 was stock with the 465. Had it came with a th350 I would have ran it until I blew it up or had the parts together to covert it to a 4spd.

A grand to rebuild it is still pretty steep by my budget pinched wallet. Still thats cheaper than other rebuilds I've heard of.

I'm gonna need a clutch sometime and that's where money spent is going to pay off. going to have to refrain from buying a cheapo clutch set...

Can't wait for a possible post turkey day snow bash run. Ride on!

manimal · 11-12-2006, 03:09 AM

I agree with both of you. I have a built TH400 in my 72 2wd behind a BBC and wouldnt trade it for nothing. But I think for now I might keep the 465 in my one ton 4x4.Both have there pluses/minuses.I really appreciate all the advice from all.-Lance

11-02-2006, 03:23 PM	#1
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	4spd or th400 I am getting ready to start the build-up of a 496 stroker BBC to put in my 1 ton 4x4.It currently has a SM465 trans and a NP205 transfer case.My question is will this 4 spd handle this kind of engine or should I swap in the th400?

11-02-2006, 09:18 PM	#2
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	Re: 4spd or th400 it will handle that no problem, just make sure you have a good clutch. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

11-03-2006, 02:44 AM	#3
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: 4spd or th400 Ya, with a good clutch it should be able to handle it no problem. __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

11-03-2006, 04:26 AM	#4
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	Re: 4spd or th400 I agree, the 4spd will handle it, no doubt. My question would be, do you really want it? A 4spd tranny isn't the best choice for hard wheeling IMO. What's the purpose for the build? Mall cruiser or actual wheeling? What tire size/gears are you ending up with? Lift? What axles are you running? Any other mods?

11-03-2006, 09:46 AM	#5
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: 4spd or th400 No I'm not going to be rock crawling, but I do plan on playing inthe mud,going camping with the family,playing in the snow,and alot of towing. The axles that I have a re a dana 60f with 4.56 and a 14 bolt ff in the rear with the same gears. Right now I am running BFG mud terrains 35x12.50x16.5. I do have a built TH400 but its 2wd. So I called Advanced Adapters,and they have an adapter and input shaft to use the 2wd trans for about $600. So maybe I'll go that way.

11-06-2006, 10:19 PM	#7
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,458	Re: 4spd or th400 If/when you get to that point I have the adaptor and the t-case----all rebuilt

11-07-2006, 09:56 AM	#8
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: 4spd or th400 Great I'll keep that in mind

11-09-2006, 05:29 PM	#10
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: 4spd or th400 Yeah I have been talking to some friends and they say the same thing,so I think I might keep my 465/205. I will probably run a centrforce dual friction clutch. THANKS EVERYBODY!

11-10-2006, 02:07 AM	#11
Bad71chev406sbc Registered User Join Date: Nov 2006 Location: Boring, Oregon Posts: 162	Re: 4spd or th400 yup....the 465s are pretty much bullet proof. A good clutch is an absolute must....stg 2 or 3 centerforce. I've got a friend that's swapping in a 465/205 instead of his th400/205....he's blown up about 14 of these. I guess th400s can't handle 44's and 400hp. It actually cracks the cases straight in half in the middle. __________________ '71 SNB, 406sbc, TH350 w/ Transpak & Starshifter, 12bolt w/ 3.73s, 2" Early Classic front coils, 2.5" Flowmaster Super 40's Last edited by Bad71chev406sbc; 11-10-2006 at 02:07 AM.

11-10-2006, 03:09 PM	#13
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: 4spd or th400 the only time I have ever cracked a case is when the slip yoke was worn out and caused the driveshaft to vibrate in my 76 k20

11-10-2006, 03:50 PM	#14
Zoomad75 K5Camper Join Date: Mar 2004 Location: Pueblo, CO Posts: 1,513	Re: 4spd or th400 I think we are going to have to agree to disagree. I'll admit with enough money put into any part, it should perform better than stock. But, while my 465 is stone stock you have to put $$$$ into any auto (th350 or 400) to make it work like the stock 465 does. Converter's and full manual valvebodies cost money as does the labor of some auto trans tech to put it together. Sure you can re-gear an auto with a lower ratio panetary set for added low range, but those gearsets are not cheap either. Sure a fully preped auto can crawl. Heck most of the pro rock crawlers are using Powerglides for that matter. But as far as Joe Schmoe weekend warrior goes, you can't beat the bang for the buck a 465 gives with all it's stoutness and versitility. And as far as fineese on the rocks and crawling are concerned, I do just fine. Last trail I ran had large section of rocks with a steep rocky climb out of a river bed. 4lo, Granny, picked my line and idled over it. Both hands on the wheel and my left foot resting on the floor. coming down I did the same thing. never touched the brakes or the clutch. Can't overheat my 465 either.... __________________ Rob Z. 1975 K5 350/465/205/D44/12b 4" lift on 35's- RIP 1991 K5 8.1L/NV4500/241/D44/14b FWC Camper

11-10-2006, 06:36 PM	#15
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	Re: 4spd or th400 Well said Zoomad75. I concur. Couple things I didn't disclose earlier. 1st - I'm running a doubler with 5:13 gears which gives me better than 100 to 1 ratio when in low/1st. 2nd - my th-400 was rebuilt for only 1K using off the shelf parts along with another 2wd tranny I already had. (spraggs came from the 2wd) They added an extra clutch plate and worked it so it has the compression braking of a standard. Pretty basic build in reality. If your out Wheeling, it's all good.

11-10-2006, 07:10 PM	#16
Zoomad75 K5Camper Join Date: Mar 2004 Location: Pueblo, CO Posts: 1,513	Re: 4spd or th400 Well, adding another 2:1 reduction into the drivetrain, would have a big impact on cawling as would 5.13's, plus the torque multiplcation of the converter itself. I'm lucky, my K5 was stock with the 465. Had it came with a th350 I would have ran it until I blew it up or had the parts together to covert it to a 4spd. A grand to rebuild it is still pretty steep by my budget pinched wallet. Still thats cheaper than other rebuilds I've heard of. I'm gonna need a clutch sometime and that's where money spent is going to pay off. going to have to refrain from buying a cheapo clutch set... Can't wait for a possible post turkey day snow bash run. Ride on! __________________ Rob Z. 1975 K5 350/465/205/D44/12b 4" lift on 35's- RIP 1991 K5 8.1L/NV4500/241/D44/14b FWC Camper Last edited by Zoomad75; 11-10-2006 at 07:11 PM.

11-12-2006, 03:09 AM	#17
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: 4spd or th400 I agree with both of you. I have a built TH400 in my 72 2wd behind a BBC and wouldnt trade it for nothing. But I think for now I might keep the 465 in my one ton 4x4.Both have there pluses/minuses.I really appreciate all the advice from all.-Lance



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