Big Block with compound 4 speed? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Shyguy · 03-14-2010, 10:52 PM

Did any of our trucks come from the factory with a big block and 4 speed compound transmission?

This weekend we put a 454 out of a '74 C-30 in my '71 C-10 using the big block motor mounts from the '74.

No one told us we could not do it so we did it.

We finished late today so I did not get a chance to take any pictures of the engine installed.

Here is the sleeper, I call it, we put the 454 in.

Danny

JimKshortstep4x4 · 03-15-2010, 05:51 AM

The brochure I have lists the 400 engine and 4 speed transmission as "available" so the combo could be ordered.

Jim

Blazer1970 · 03-15-2010, 05:59 AM

What's a "compound" 4 speed?

Shaky · 03-15-2010, 06:04 AM

Quote:

Originally Posted by Blazer1970

What's a "compound" 4 speed?

This. I'm intrigued...

Shyguy · 03-15-2010, 09:53 AM

Quote:

Originally Posted by Blazer1970

What's a "compound" 4 speed?

My memory is not as good as it once was so I called the top loader, near bullet proof, transmission a compound 4 speed. That is what we called it in the old days.

Low gear is real low and normally only used when taking off pulling a very heavy load. Most every day driving people take off in 2nd.

Quite a few people like the automatics instead, but I like the old heavy duty transmissions better. Both of my trucks have them.

Heck, if you put one in low gear and let the truck idle you can walk faster. I have heard that some old timers use to do just that with their trucks in the field while they threw stuff in the bed of the truck or on a towed trailer. Of course they had to tie the steering wheel in place.

I am suffering from CSR right now and can not remember the number designation of the transmissions.

Danny

dan42 · 03-15-2010, 10:13 AM

SM465 - and I've seen a '70 big block flat bed with that 4-speed in it before.

Shyguy · 03-15-2010, 10:35 AM

Quote:

Originally Posted by dan42

SM465 - and I've seen a '70 big block flat bed with that 4-speed in it before.

Thank you.

I think that is what my '71 has now that you mention it.

My '67 has the SM420 probably since the reverse gear is in a different place.

After driving my truck some last night the 454 with the RV cam, headers and the 4 speed transmission with 3.73 gears seem to be a good match.

I was afraid it would happen, the stock starter seems to be the weak link. When I tried to start it after it set a little while the engine would only turn over real slow. It did start luckily so I guess I will have to now figure out how to fix that.

Danny

**kwmech** · 03-15-2010, 10:56 AM

My big block GMC has an NP435 trans in it, 4-1 first instead of the 6-1 that is in the 465

Shaky · 03-15-2010, 11:56 AM

Big-block and SM465 is a nice combo. Just don't hammer it in first gear.

69GMCLonghorn · 03-15-2010, 12:47 PM

Quote:

Originally Posted by kwmech

My big block GMC has an NP435 trans in it, 4-1 first instead of the 6-1 that is in the 465

GMC was known for using the NP435 in a lot of their trucks. That is what mine had. There were 2 different NP435's, as you stated. The newer ones had the 4:1 first gear. The older ones had the 6.9:1 first, which is what mine had. I think the 4:1 is a much more usable granny gear. If you really NEED the 6:1, you are overloaded!

03-14-2010, 10:52 PM	#1
Shyguy Junior Member Join Date: Dec 2006 Location: Southeast Missouri Posts: 2,436	Big Block with compound 4 speed? Did any of our trucks come from the factory with a big block and 4 speed compound transmission? This weekend we put a 454 out of a '74 C-30 in my '71 C-10 using the big block motor mounts from the '74. No one told us we could not do it so we did it. We finished late today so I did not get a chance to take any pictures of the engine installed. Here is the sleeper, I call it, we put the 454 in. Danny Attached Images __________________ '67 Chevy C-20 short stepper - build complete, 454/SM-465. '75 C-30 Single Cab DRW-350 small block/NP-435. '77 GMC-6500 Dump Truck, 427 Tall Deck. '92 GMC K-3500 Duallie, 454/4L80E.

03-15-2010, 05:51 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Big Block with compound 4 speed? The brochure I have lists the 400 engine and 4 speed transmission as "available" so the combo could be ordered. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

03-15-2010, 05:59 AM	#3
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,510	Re: Big Block with compound 4 speed? What's a "compound" 4 speed? __________________ Tim

03-15-2010, 10:13 AM	#6
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: Big Block with compound 4 speed? SM465 - and I've seen a '70 big block flat bed with that 4-speed in it before. __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

03-15-2010, 10:56 AM	#8
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,483	Re: Big Block with compound 4 speed? My big block GMC has an NP435 trans in it, 4-1 first instead of the 6-1 that is in the 465

03-15-2010, 11:56 AM	#9
Shaky Six in a row makes it go... Join Date: Mar 2009 Location: Vacationland: Maine Posts: 1,346	Re: Big Block with compound 4 speed? Big-block and SM465 is a nice combo. Just don't hammer it in first gear. __________________ 67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce



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