[mlmvl]

I am picking up this project today.

1967 Firebird convertible 400. He had the original 400 but traded it for a 454 motor that needs to be re-built. I am pulling the numbers from the block, heads, and intake manifold. I want to figure out what year motor it is. It has 7.4L G stamped on it which I thin means it is something out of the 80's.

[Silverlsinva]

I would guess something out of a truck? And congrats on the new project gonna do a build up show and tell?

[Firefighter]

In the 80's that was the only place they used the BBC.

Sent from my friggin Droid by two thumbs using Tapatalk 2 or whatever the ish it's called....

[ChrisBlair]

Originally Posted by mlmvl

I am picking up this project today.

1967 Firebird convertible 400. He had the original 400 but traded it for a 454 motor that needs to be re-built. I am pulling the numbers from the block, heads, and intake manifold. I want to figure out what year motor it is. It has 7.4L G stamped on it which I thin means it is something out of the 80's.

The 454 won't mate up to a BOP trans. To be honest, you're better off with a 400 RA IV build up. There have got to be a billion Poncho clubs to help you out

...and I hope the 454 is in the shed, because there ain't no mill in that car

[Firefighter]

Was there three trans patterns? I know there was a Chevy then a Pontiac. Wasn't there a Corporate dual pattern? Or something like that.

Sent from my friggin Droid by two thumbs using Tapatalk 2 or whatever the ish it's called....

[ChrisBlair]

Originally Posted by Firefighter

Was there three trans patterns? I know there was a Chevy then a Pontiac. Wasn't there a Corporate dual pattern? Or something like that.

Sent from my friggin Droid by two thumbs using Tapatalk 2 or whatever the ish it's called....

I don't know how many there were but BOP had commonality. I don't know the reason

Buick Olds and Pontiac used a common pattern and Chevies were different...Not sure about GMC and Caddy. I don't know when that stopped but I'm confident it was in place in '67. I know it was for '74; I still have a TH400 long tail that was hooked up to my '74 Buick 455 bloc,k and it has the BOP pattern without doubt- bolted right up to my Buick transmission built in 1969.

There are adapters though. There might be a corprosate dual pattern in the mid to late 70s and 80s, but in the '60s the divisions hadn't been corralled into the corporate lagoon yet. I feel very confident there is going to be a tranny pattern issue with that Poncho using a Chevy engine. No deal breaker, just a mild PITA- might already have the Chevy trans for all we know.

[Firefighter]

All of your post is ringing accurate now that I'm thinking about it.

If it were me I would be updating the drivetrain. I would be looking at something LS based and getting some sort of 6 speed trans at minimum. Especially with all the motors out there now and the ease of swaps through the aftermarket.

Sent from my friggin Droid by two thumbs using Tapatalk 2 or whatever the ish it's called....

[LStick]

Originally Posted by Firefighter

All of your post is ringing accurate now that I'm thinking about it.

If it were me I would be updating the drivetrain. I would be looking at something LS based and getting some sort of 6 speed trans at minimum. Especially with all the motors out there now and the ease of swaps through the aftermarket.

What a treasure !

If it were me, I'd be nut and bolting it back to a full restoration. A first year convert has to be super rare, and worth the effort.

Your car ....Your decision.....Great find !!!!!!!!!!

[05stram]

Originally Posted by ChrisBlair

I don't know how many there were but BOP had commonality. I don't know the reason

Buick Olds and Pontiac used a common pattern and Chevies were different...Not sure about GMC and Caddy. I don't know when that stopped but I'm confident it was in place in '67. I know it was for '74; I still have a TH400 long tail that was hooked up to my '74 Buick 455 bloc,k and it has the BOP pattern without doubt- bolted right up to my Buick transmission built in 1969.

There are adapters though. There might be a corprosate dual pattern in the mid to late 70s and 80s, but in the '60s the divisions hadn't been corralled into the corporate lagoon yet. I feel very confident there is going to be a tranny pattern issue with that Poncho using a Chevy engine. No deal breaker, just a mild PITA- might already have the Chevy trans for all we know.

Like he said the BOP pattern will have the top of the trans bell housing with a swag if you will and the Chevy pattern will come up into a peak sort of. Yes there was a combined pattern in the late 70s but I believe it did not start until the metrics came about. Somebody may correct me if I am wrong but it has been a while since I had to worry about bell housings.
Chris wasn't there a difference in the BB and SB bell housings as well in the BOP pattern? seems to me there was I cannot remember.

[ChrisBlair]

Originally Posted by 05stram

Like he said the BOP pattern will have the top of the trans bell housing with a swag if you will and the Chevy pattern will come up into a peak sort of. Yes there was a combined pattern in the late 70s but I believe it did not start until the metrics came about. Somebody may correct me if I am wrong but it has been a while since I had to worry about bell housings.
Chris wasn't there a difference in the BB and SB bell housings as well in the BOP pattern? seems to me there was I cannot remember.

The 1974 Buick 455 that I yanked out of a Riviera bolted right up to the original TH350 in my '70 Buick; that car originally had a Buick 350 that needed the top end redone. It was cheaper to buy an entire car just for the engine and transplant it! Buick didn't really have a 'big block' and a 'small block' per se, they didn't really worry about that, although the parts don't interchange. Incidentally, nothing is a swap on the Buick Olds or Pontiac 455s either. GM practically burned money in those days

My 455 engine inflicted bloody murder on my TH350 of course, but it bolted up with no problems

[trademaster]

Looks like a nice project. Beautiful dogs too.

[shank0668]

Not to highjack, but I have a TH350 BOP in my garage if someone wants it...
Now if it's an 80's motor, it is definitely a truck 454. I would seriously go back to a Poncho 400 in it.
Looks like a good project!

[mlmvl]

Here are a few of the numbers.