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-   -   Putting miles on 67, 402bbc VS 67 V6 305E (https://67-72chevytrucks.com/vboard/showthread.php?t=844302)

geezer#99 05-09-2023 10:30 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Here’s a mileage kicker for you!
Bought a 70 chevelle ss454 back in 1978. LS6, m22 and 3.08 gear. Previous owner didn’t like the solid lifter cam so he had a stock bb cam installed. Same basic cam as in your 402.
Highway driving at 65 mph it would get 22 mpg. That’s a Canuck gallon. Same as 18 mpg in US gallons. While it sipped fuel it was a real dawg to drive. Ran out of breath at 4500 rpm.
Drove it like that over the winter. In the spring swapped the cam to a LS6 spec but it was a hydraulic cam.
Took care of that gas sipping dawg. Dropped it back to 15 mpg in Canuck gallons. Awesome power difference. Would light em up all the way thru 3rd even with the 3.08 gear.
And now back to your regular programming.

67km1590 05-09-2023 10:55 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Could you call me, five one three, five one eight, three five zero one.

1967GMCC20 05-09-2023 11:03 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by geezer#99 (Post 9202748)
Here’s a mileage kicker for you!
Bought a 70 chevelle ss454 back in 1978. LS6, m22 and 3.08 gear. Previous owner didn’t like the solid lifter cam so he had a stock bb cam installed. Same basic cam as in your 402.
Highway driving at 65 mph it would get 22 mpg. That’s a Canuck gallon. Same as 18 mpg in US gallons. While it sipped fuel it was a real dawg to drive. Ran out of breath at 4500 rpm.
Drove it like that over the winter. In the spring swapped the cam to a LS6 spec but it was a hydraulic cam.
Took care of that gas sipping dawg. Dropped it back to 15 mpg in Canuck gallons. Awesome power difference. Would light em up all the way thru 3rd even with the 3.08 gear.
And now back to your regular programming.

Very cool story. 3.08 gears would favor stock low speed, high torque cam. With that gear, you can win "farthest distance awards"... my truck runs great, but needs OD or lower gears. I do like going up hills in drive with 4.10s.

Bob B. 05-09-2023 11:53 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by factorystock (Post 9202060)
When GM started offering the 396-402 in 3/4 tons, a 3.54 Dana became standard equipment, but, if you have the wallet......................

Biggest problem with the V-6 in pickups was GMC usually geared them too low.

Ironangel 05-09-2023 07:30 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by RustyPile (Post 9202009)
Got a 454 in my '71.. It's a disease I tell you. The first symptom is you go around with a smile on your face. Also makes you forget about gas mileage..

No Lie My Brutha! I've always said "if your worried about gas mileage your drivin the wrong truck..." ;)

jimijam00 05-09-2023 10:55 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by 67km1590 (Post 9202756)
Could you call me, five one three, five one eight, three five zero one.

I think I saw that phone number on a bathroom wall at Playpen Gentleman's Club. The name above the number was Trisha.

1967GMCC20 05-10-2023 07:33 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
My 67 has Patina, but when I open hood with BBC 402, people step back woooo. Is Big Block that big a deal in trucks?

MJN 05-10-2023 01:50 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by 1967GMCC20 (Post 9202734)
So the rear X member on bell housing is same. Mine is all there. The engine Bell housings were SAE, so I suspect similar.

I chisled the rivits, not torched.

I have the dust shield from Bell housing. Got left behind when I sold engine.

Not to hijack but I have a GMC V6 to SM420 bellhousing. They're not SAE patterns, http://67-72chevytrucks.com/vboard/s...mc+bellhousing

71CHEVYSHORTBED402 05-10-2023 03:32 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
My 402 just recently came back to life after a 7 yr. hibernation, SWB truck. It's a low mileage rebuild, I only installed new pumps, timing and such since. It runs better than it ever has, I couldn't be happier. It's not quite stock, the heads are 1967 GM HP 396, Delco HEI distributor and high RPM cam.

Differential is a low RPM under-achievement at 3.73:1, there's no burning tires in first gear. On shift it can chirp, that's it. But loves the highway, it just wants to fly. That's what I've always liked about it. No matter how steep a hill it gains speed under little acceleration, and without more.

1967GMCC20 05-10-2023 04:17 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by MJN (Post 9203035)
Not to hijack but I have a GMC V6 to SM420 bellhousing. They're not SAE patterns, http://67-72chevytrucks.com/vboard/s...mc+bellhousing

Well I got that from 6066. V6 site, they have volumes on the V6. Just checked. Bet it was the larger V6, Larger trucks with 5spd. https://www.smokstak.com/forum/threa...gmc-v6.145198/

I mis read that on the GMC site on design of the engine. V12, large HD truck V6.

Your trans, bolts to my bell housing, same as NP435G (the real 4spd).

jimijam00 05-11-2023 12:44 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by 71CHEVYSHORTBED402 (Post 9203052)
My 402 just recently came back to life after a 7 yr. hibernation, SWB truck. It's a low mileage rebuild, I only installed new pumps, timing and such since. It runs better than it ever has, I couldn't be happier. It's not quite stock, the heads are 1967 GM HP 396, Delco HEI distributor and high RPM cam.

Differential is a low RPM under-achievement at 3.73:1, there's no burning tires in first gear. On shift it can chirp, that's it. But loves the highway, it just wants to fly. That's what I've always liked about it. No matter how steep a hill it gains speed under little acceleration, and without more.

A big block with 3.73s should be melting tires. What's wrong with yours?

1967GMCC20 05-11-2023 06:08 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
I have not opened 4 barrel yet, still enjoying cruising.
Kinda wonder how it would run down qtr mile.


Hauled 10ft posts for grapevines today from Farm Store.

71CHEVYSHORTBED402 05-11-2023 09:08 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by jimijam00 (Post 9203245)
A big block with 3.73s should be melting tires. What's wrong with yours?

Couldn't tell you. It's never burned off go, or very little.

Steeveedee 05-11-2023 09:34 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Weird. If I cob mine, even with the shell on it and a 3.56 axle, it'll lay rubber and chirp second. No wheelies like the farm truck, though. :lol:

71CHEVYSHORTBED402 08-02-2023 11:26 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by Steeveedee (Post 9203379)
Weird. If I cob mine, even with the shell on it and a 3.56 axle, it'll lay rubber and chirp second. No wheelies like the farm truck, though. :lol:

Right, and my block sports HP heads off a 67ish 396 SS.

Don't mind me, I don't know what I'm talking about. First off my kick down never worked. Second I had 8" wheels and 70s, so on and so forth, and I probably baby it too much. Everything works now, lots rebuilt, timing chain, trans., axle, carb. etc. I just changed the oil today and figured it's time to really test her out. It runs like a bat out of hell, I'm really surprised. Burns rubber all kinds of ways, but I still refuse to jump from a dead start:lol: Too many rocks.

1967GMCC20 08-03-2023 08:17 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
BBC Keeps running good. Hooking up neutral safety on Lokar shifter today. Thought about that when was going to let someone take it for a spin.

It's amazing how smooth this engine 402bbc runs. Torque is definitely big block.

1967GMCC20 08-03-2023 08:20 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Next will be adding trailer brake controller so I can pull car hauler.

68panelman 08-03-2023 08:47 AM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Show us some pictures of this beast..;)

71CHEVYSHORTBED402 08-03-2023 02:47 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Quote:

Originally Posted by 68panelman (Post 9226287)
Show us some pictures of this beast..;)

I'd like to hear it too:smoke::chevy:

1967GMCC20 08-03-2023 09:30 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Have not figured out wonky photo upload process. If it takes more than 3 steps...forget about it.

1967GMCC20 08-04-2023 12:04 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Can see no pic attachment, what is this the Zuckerberg software?

1967GMCC20 08-04-2023 07:18 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Just ordered a vintage NOS Kelsey Hayes brake controller fir 67 GMC. Now I can have trailer brakes on the oldie.

1967GMCC20 08-04-2023 07:57 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
Still have NP435G from truck.

1967GMCC20 08-27-2023 03:28 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
2 Attachment(s)
Pics

1967GMCC20 08-27-2023 03:35 PM

Re: Putting miles on 67, 402bbc VS 67 V6 305E
 
2 Attachment(s)
Adding Kelsey Hayes brake controller for pulling trailer.


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