73 Charger.... need some advice

[drobertson]

Well a few months ago I bought a 1973 Charger for $500. My initial plan was to rebuild the 318 and 727, which I already did. However, I scored a 440/727 combo from a relative for $150. I really want to do the 440 swap, but I wanted to ask a few questions to clarify my confusion.

So I either need a 73-74 b body RB k frame, or I could buy the shumacher motor mounts. I have heard that the schumacher mounts position the engine higher than stock, so I was wondering if that was true and whether I should be worried about hood clearance with a regular non-bulge hood.

I would be interested in a k frame if any of yall have one you'd sell for a decent price...

From what I know, I'll also need to upgrade my rear end assembly to at least a 8 3/4 from the tiny 8 1/4. Since both engines have a 727 TQ, would I have to extend/ shorten the driveshaft to upgrade the diff? Also what gears would you recommend? I like the 3.23 for moderate MPG and acceleration...

I know that I'll need to upgrade my radiator, but does anybody have insight as to which side the hose went to on a 73 big block car? I appreciate any and all replies. :headbang:


I just can't wait until I'm tearing up the streets!

 

[Chargerjase]

Ok, I am not an expert on all things you have asked and I know others will chip in. The question is, what are you going to do with the 440? Will it be stock with 4bbl carb or new cam, intake, headers, stroked etc. If you are going to make serious horse power then you need to beef up your rear end. The 8 1/4 is surprisingly strong and was used in big block cars in 73. The hp cars got the 8 3/4 but if its going to be a stock build then leave the 8 1/4 for now.
My 73 Charger is a 400cid with AC and came with the 28 inch radiator. The hoses are on the passengers side.
Hope this helps some.

 

[Nacho-RT74]

SB and BB TQs are 50 cfms difference by the primary bbls bore.

Need bigger radiator with correct outlets setup. Need to note up to 72, the water pump housing got the lower outlet on driver side, since 73 changed to passenger side. Which year 440 you got ? On both setups the upper got the watter outlet on passenger side.

this changes also the steering pump setup, brackets and pulleys, specially on AC cars... same year crossover, between 72 and 73. MOSTLY SURE because by smogger era, lates big cars got an air pump setup for the carb located where the older steering pump location was. These blocks got a provision threated on block for the steering pump assembly.

This is of course if you want to build a full correct 73 and lates setup. You can build an early setup on a late car if you want anyway

Steering pump pressure hose changes too with BBs

Bigger T bars and sway bars are an advice ( depending on the ones you got on car at this moment ). Stock 73 and lates BB are .92" ( or .96" ? ) T bars and 15/16" sway bar if I remember correctly.

will need to get enlarged AT LEAST coil and dist wires on engine harness... thats if the actual water sender and alt wires are large enough.

as mentioned, 8.25" will hold the 440 torque on street use, even more if is a cast crank ( smogger era ). But is true could be nice to get a 8.75", even more if you ad some vitamins on engine.

Gas line is diff too. Can be home made or ordered ( they are being sold ready to install )

Carb linkage system is diff. Honestly I will get it used around.

Drive shaft is a must if you change the axle. I think you can live with the one you have at this moment keeping the 8.25" yet

3.23 is quite good for all around use. 3.55 is nice too. ( I made the change from 3.23 to 3.55... I was happy with both )

If you get the axle, get it with drums assembly. Bigger blocks cars got the bigger drums setup ( 11" and 3" width I think ? )

shumacher mounts seems to fit the engine at same height by a thread being talked at this moment on dc.com board, asking exactly the same question

 

[Montclaire]

I would not run an 8 1/4 behind anything with torque and I would question if it was actually available behind a big block or not in 73.

 

[Nacho-RT74]

I think have seen some 73 and lates BB with 8.25 around... maybe 400 2 bbls? can recall, but pretty sure some are.

 

[YY1]

I have a 1987 D100 long bed truck...with an 8 1/4!

It is a 225/833 O/D, but it's a 4400 pound long bed manual trans truck.

 

[drobertson]

Ok, I am not an expert on all things you have asked and I know others will chip in. The question is, what are you going to do with the 440? Will it be stock with 4bbl carb or new cam, intake, headers, stroked etc. If you are going to make serious horse power then you need to beef up your rear end. The 8 1/4 is surprisingly strong and was used in big block cars in 73. The hp cars got the 8 3/4 but if its going to be a stock build then leave the 8 1/4 for now.
My 73 Charger is a 400cid with AC and came with the 28 inch radiator. The hoses are on the passengers side.
Hope this helps some.

I do plan on adding power to the 440 with higher compression (10:1), headers, dual exhaust, edelbrock intake manifold, edelbrock carburetor, hp cam, and a decent converter. I will eventually put a 8 3/4 or dana in it, but I'm concerned as the whether the 8 1/4 would be safe for a few months.

 

[drobertson]

SB and BB TQs are 50 cfms difference by the primary bbls bore.

Need bigger radiator with correct outlets setup. Need to note up to 72, the water pump housing got the lower outlet on driver side, since 73 changed to passenger side. Which year 440 you got ? On both setups the upper got the watter outlet on passenger side.

this changes also the steering pump setup, brackets and pulleys, specially on AC cars... same year crossover, between 72 and 73. MOSTLY SURE because by smogger era, lates big cars got an air pump setup for the carb located where the older steering pump location was. These blocks got a provision threated on block for the steering pump assembly.

This is of course if you want to build a full correct 73 and lates setup. You can build an early setup on a late car if you want anyway

Steering pump pressure hose changes too with BBs

Bigger T bars and sway bars are an advice ( depending on the ones you got on car at this moment ). Stock 73 and lates BB are .92" ( or .96" ? ) T bars and 15/16" sway bar if I remember correctly.

will need to get enlarged AT LEAST coil and dist wires on engine harness... thats if the actual water sender and alt wires are large enough.

as mentioned, 8.25" will hold the 440 torque on street use, even more if is a cast crank ( smogger era ). But is true could be nice to get a 8.75", even more if you ad some vitamins on engine.

Gas line is diff too. Can be home made or ordered ( they are being sold ready to install )

Carb linkage system is diff. Honestly I will get it used around.

Drive shaft is a must if you change the axle. I think you can live with the one you have at this moment keeping the 8.25" yet

3.23 is quite good for all around use. 3.55 is nice too. ( I made the change from 3.23 to 3.55... I was happy with both )

If you get the axle, get it with drums assembly. Bigger blocks cars got the bigger drums setup ( 11" and 3" width I think ? )

shumacher mounts seems to fit the engine at same height by a thread being talked at this moment on dc.com board, asking exactly the same question

I'm not doing a stock style 440, as I'm definitly going to be making more power and removing the emissions stuff. The year of my 440 is unknown, but I do know that it's a later cast crank 440. Here's a picture:

 

[drobertson]

So what is the difference between the power steering pumps and hoses between big and small block cars? I noticed that the big block one has cooling fins, whil my current small block one doesn't.

 

[ODZKing]

Both hoses are passenger side on big block 400 anyway.

 

[Chargerjase]

I would not run an 8 1/4 behind anything with torque and I would question if it was actually available behind a big block or not in 73.

Here is a copy of my broadcast sheet.
E63 = 400 cid 2 Barrel V8 175HP
D82 = 8.25" Axle

 

[hemihead]

As far as K members go , you can pick up a K from a 400 car and it's the same .

 

[moparmarks]

I have a 74 Coronet 400 4-bbl with the 8.25 rear.

 

[Montclaire]

Doesn't say too much for the 400, does it? haha

 

[YY1]

...or it says a lot for the 8 1/4!

 

[ODZKing]

Yeah, interesting.
The 73 - 400 2bbl puts out less horse power than the 67 - 273 2bbl.
Compression 8.8-1(273) and (400) 8.2-1 according to the numbers I see on My Mopar.

 

[YY1]

Careful- Net (72 and up) vs Gross (71 and down).

On a net to net basis, however, the roller cam moly ring Magnum 5.9 puts out more than the 73 400 and almost as much as the 73 440!

...and they're good for 200,000 give or take.

Something to think about versus swapping all that over for a BB.

 

[Bruzilla]

I do plan on adding power to the 440 with higher compression (10:1), headers, dual exhaust, edelbrock intake manifold, edelbrock carburetor, hp cam, and a decent converter. I will eventually put a 8 3/4 or dana in it, but I'm concerned as the whether the 8 1/4 would be safe for a few months.

I've run several 73 Roadrunners with 440s and 8.25 rears without any problems. But I was just street driving and racing and not doing anything too extreme.

 

[YY1]

I'm fairly certain I've seen 400 4 barrel Cordobas with 8 1/4 under them.

 

['68 Charger]

I'll add to the 8.25 rear end being in a 1973 BB.

I'm currently parting out a 1973 Satellite 400 2bbl and it has the 8.25 rear end with 2.71 ratio.