Big Block Into a Small Block Sub Frame

[BDR529]

I've heard a lot of different things over the last few years and I'm just looking for some clarification. Can I buy a 440/727 combo and drop it into a 75 C-Body with a small block subframe? I've heard yes, no, yes but the transmission won't line up, and yes if you buy schumacher engine mounts. Any clarification?

 

[has2bmopar]

I've heard a lot of different things over the last few years and I'm just looking for some clarification. Can I buy a 440/727 combo and drop it into a 75 C-Body with a small block subframe? I've heard yes, no, yes but the transmission won't line up, and yes, if you buy schumacher engine mounts. Any clarification?

I would go with this one.

Give them a call, I know they work for a '74 Charger, and I would guess the same mounts will work on the C-body, but... call to be sure first.

 

[BDR529]

Thanks, I'll give them a call soon to see if it'll work out. I was just wondering if anyone had any experience in a 74-77 C-Body specifically, I've heard a lot of "shoulds" and "maybe's" and "technicallys"...

 

[commando1]

Thanks, I'll give them a call soon to see if it'll work out. I was just wondering if anyone had any experience in a 74-77 C-Body specifically, I've heard a lot of "shoulds" and "maybe's" and "technicallys"...

Ask away.

By the way, the subframe and their motor mount attachment brackets are the same for small blocks and big blocks on these cars. Just the motor mounts are different. And NOS ones are still available and relatively cheap on ebay.
The SB to BB swap will be a piece of cake.
Don't need Schumacher. I'm assuming there's a 360 in there, right?

 

[BDR529]

Yes it's a 360. Over on that blues brothers forum that every here is so disappointed in they found there actually are slight differences in the big block and small block sub frame. And there's a derby guy who says that you can drop a small block into a big block frame, but it's difficult and offsets the transmission. So it'll fit, but it causes severe binding on the mounts, which is the assumption and questioning coming into play about a big block into a small block swap...
Here's a link to the thread with an excessive discussion about the frames, if anyone wants to venture over to the dark side"
http://bluesmobiles.proboards.com/index.cgi?board=details&action=display&thread=370

 

[commando1]

That there is some extremely interestering stuff!
I shot from the hip because I saw it done. I asked him how was it and he descibed it the way I did to you. I still think you're good to go

Great research on your end! Well done

(Sent using Forum Runner)

 

[BDR529]

Thanks! I try to do research before making posts, I always feel so disappointed in myself whenever I ask a question and get referred to another post, haha.

 

[Stormer]

So, it sounds like the answer is yes, you can do it but you may need to move a couple of things around. So, go for it. I'm sure you didn't expect it to be simple.

 

[has2bmopar]

Ask away.

By the way, the subframe and their motor mount attachment brackets are the same for small blocks and big blocks on these cars. Just the motor mounts are different. And NOS ones are still available and relatively cheap on ebay.
The SB to BB swap will be a piece of cake.
Don't need Schumacher. I'm assuming there's a 360 in there, right?

Stan, your source is jacking you around, the sub-frames and K-frames are different between the small block and big block starting in '73. The big block frames have the perches moved farther back than the small block.

 

[commando1]

Stan, your source is jacking you around..

Had you waited to read the whole thread, you would have seen that I said I stand corrected....
And accordimg to the Blues guys, it's not brain surgery to make the alteration necessary to git'er done.

 

[BDR529]

See, us bluesmobile guys aren't all​ bad.. I know it's not up many peoples ally, but there really is a lot of good info in the "Dodge Monaco Stuff" section for anyone interested...

 

[Stormer]

See, us bluesmobile guys aren't all​ bad.. I know it's not up many peoples ally, but there really is a lot of good info in the "Dodge Monaco Stuff" section for anyone interested...

I am so amused by this. I had no idea this existed & it's not my thing but I love it.

 

[commando1]

They certainly do have the knowledge. It's what they do with it... :rolling:

 

[BillGrissom]

I imagine you know that you need a BB transmission.

What are your goals with the car? If daily driving, I would recommend considering installing a 5.9L Magnum small block. That would give you much better mileage with EFI and an over-drive tranny and if it can move a 5000 lb truck, it should move your lighter car. People who do this in an A-body must cut their tranny tunnel, but maybe not for a C-body (anyone tried?). I doubt you are drag racing with a C body.

 

[Stormer]

I imagine you know that you need a BB transmission.

What are your goals with the car? If daily driving, I would recommend considering installing a 5.9L Magnum small block. That would give you much better mileage with EFI and an over-drive tranny and if it can move a 5000 lb truck, it should move your lighter car. People who do this in an A-body must cut their tranny tunnel, but maybe not for a C-body (anyone tried?). I doubt you are drag racing with a C body.

5.7 is tried, true & strongly supported by the aftermarket.

 

[BDR529]

Well due to the movie, she has to have a 440. I just found a 440 mounted to a 727 I'm picking up tomorrow. It'll be a no rush, build as I can afford project, so hopefully the schumacher mounts are as drop in as they sound and the transmission will line up right and it'll be pretty plug and play! As far as my goals, not daily driver, but nice weekends. I want it to run on the lowest grade gas possible and have the deep, throaty sound a 440 should...

 

[commando1]

. I want it to run on the lowest grade gas possible and have the deep, throaty sound a 440 should...

The CR on those late 440's were so low you could run them on Mexican gas with no knock.

 

[Stormer]

The CR on those late 440's were so low you could run them on Mexican gas with no knock.

HAHA what was the CR?

 

[commando1]

7.8:1 IIRC.
PLUS plenty of retarded timing and no distributer vacuum advance thrown in for good measure.

(Sent using Forum Runner)

 

[BDR529]

Well I'm looking at running a stock bore, with a mild cam and a port of the heads that are on the RV motor I just picked up. I'll be honest I'm not sure exactly what a mild cam entails, but I figure for a little more performance without getting too aggressive it should work nicely based on some previous conversations with friends. The only other thing I'm thinking about is an intake manifold. Has to fit under the stock 75 Monaco hood and that's about it...