Big Blocks

[hornz]

Hi all, was wondering if someone could help answer a question for me. Did a big block ever come factory in a 67-72 four-wheel drive pickup? I've been getting some conflicting info. and was hoping to clear it up. Thanks for any info. you can give me.

[70rs/ss]

Nope, no BBC in 4X4's at all (between 67-72), Welcome to the boards!

[streetstar]

nope, never --- but they can be retrofitted with few probs

[dan42]

Except '67 - isn't there modification required for that year?

[LONGHAIR]

There is modification needed for any of them. The distributor to firewall clearence seems to be the biggest thing, but there are other issues that need to be addressed. They are really no different/worse that any other swap though. Motor mounts/frame stands, exhaust, A/C housing, transmission crossmember, etc.

[70rs/ss]

I have a stock 74 454 in my 72 Blazer and it is mounted in the SBC position. The hei is tight but fits, and the valve covers are tigh but low OE type so they fit. If I was to do a BBC swap into a 4X4 I'd move the mounts forward about 1" and get all the room you need without having to get new driveshafts made (if the motor moves up the front shaft needs shortened and the rear shaft needs to be longer, as the transfer case and trans move forward as well). BTW stock 454 in a Blazer, WOW lots of torqu!

[BBGMC]

That cant necessarily be true because I know a guy who had a 1969 4x4 With a 396 and the factory build sheet too bad he sold it before I could get it sounds rare

[Longhorn Man]

without documentation, we're gonna put this in the class with the vette option, the small window 68, and loch ness.
40,000+ ppl on here, and no one has ever seen one, all the factory documentation geeks on here (myself included) and nothing pops up in ANY paperwork, to include the limited GMC info out there.
It never happened.

[mrein3]

Originally Posted by 70rs/ss

I have a stock 74 454 in my 72 Blazer and it is mounted in the SBC position. The hei is tight but fits, and the valve covers are tigh but low OE type so they fit. If I was to do a BBC swap into a 4X4 I'd move the mounts forward about 1" and get all the room you need without having to get new driveshafts made (if the motor moves up the front shaft needs shortened and the rear shaft needs to be longer, as the transfer case and trans move forward as well). BTW stock 454 in a Blazer, WOW lots of torqu!

Instead of moving the engine and having to do all that drive line work, why not build/buy a stout 700r4 with the Advanced Adapters "output shaft to use it in place of a th350 in front of a NP205", and use that extra nearly 2" of transmission case length to move the engine forward?

I know there are still some old timers out there who think if you can't tear up a 700r4 in one afternoon behind a big block your big block wasn't firing on all 8 cylinders. However my understanding is there are some companies that will build one and back it up behind just about any naturally aspirating big block you can bolt to it.

Once you decide to put $2000-$4000 into a big block, whats another $1500 for a stout 700r4?

[70rs/ss]

I have an $1800 700r4 behind a hairy BBC and I agree it can be done, but in my case the 4X4 is a standard and was done with the SBC stuff in the SBC location, it all fit, but if I was to redo it I'd like the motor forward more. I guess I really don't have an opinion on this as the 700 would do exactly as you said, move the motor forward and leave the transfer in it's OE place, if I do another 4X, I'll have to remember that. Thanks!

[mrein3]

Originally Posted by 70rs/ss

I have an $1800 700r4 behind a hairy BBC and I agree it can be done, but in my case the 4X4 is a standard and was done with the SBC stuff in the SBC location, it all fit, but if I was to redo it I'd like the motor forward more. I guess I really don't have an opinion on this as the 700 would do exactly as you said, move the motor forward and leave the transfer in it's OE place, if I do another 4X, I'll have to remember that. Thanks!

I've had a core 2wd 700r4 on the shop floor for a couple of years now but even at $4/gallon I can't justify the $800-$1200 to make it work behind my 383 in my 4x4 because of the few miles I put on my truck. However the 30% lower rpms on the highway would be nice the few times I buzz it up to 70 on the interstate.

To keep this thread on point, what exhaust manifolds did you use with the stock 454 in your Blazer in the stock location with SBC stuff? [by stuff I'm assuming you mean engine mounts] I have to be honest and admit that I went with my 383 because I didn't want to deal with trying to convert my truck to a big block. I did my 383 about the time YoukonJack was caving in his firewall to fit his big block in his 4x4. I have plenty of other vehicles that 383 would slide right in to to make room for a big block in my truck.

[70rs/ss]

They appear to be the stock truck manifolds. It is in there with the stock sbc mounts on the OE crossmember. I have to assume the motor is from a truck as it is a 74 or 75 model and by then the BBC weren't really coming in cars? I didn't put it in, but it is in the SBC location and I don't see any craziness done to make it fit, the hei is tight to the firewall, but I can move it to adjust the timing, and the Valve covers are the stock short ones, with no rubbing. I love it, even stock a 454 puts down some nice torq.

[hornz]

Thank you all for your input. I originally asked the question to clear up an issue with our truck pulling club. At an inspection, it was found one guy had his engine (a BB)moved forward from where it should be because it was easier than making modifications to firewall, etc. (like others in the past were forced to do). When pinched on it, it turned into an argument that BB came factory in that position. After asking around, some said they came with them and others said no they didn't. So thought, I would come to the "experts" and ask. So I guess without documentation to prove they came that way, he is SOL and will have to move it back.

[LONGHAIR]

I would say that this is where the confusion starts.
The foreward position (as in this guys pulling truck) is correct for big blocks....just not in a 4x4 (because there is no such thing). So if this is some kind of "stock class" where an incorrect motor would be illegal, he is out of luck. If it is just because of the foreward off-set (meaning illegal mounting position, because it is not stock)....how do you determine what "stock" would be? since they didn't come that way?
If he had converted a factory 2 wheel drive BB truck into a 4x4, the foreward position would be stock...........
Confused yet?

[The Big Green]

I had a 700hp 468 with a 400 shot in my 67 years ago, man I miss thoughs days....hmmm...