440 six pack stock rods crank gram weight ?

Does anyone know the bob weight of a 1973-1974 six pack rods 440 crank ? i have heard it is around 2700-2900 grams in stock form, i know this question has been asked before but i can't remember the ad. thanks to all,,,,,,,,, only check one time a day.

The rotating assembly in those engines is heavy. Heavy rods, heavy pistons, heavy pins, heavy rings, etc. Bobweight is often over 3000 grams. They rev like a tractor!

I was thinking it was in the heavy range, i have a NEW eagle crank , but it is #2550 grams, i can use it but i don't want to pay $1,000 to 1,250 for pistons ..........that is too much for a street car......lol.

2550 Is well below the bobweight for a heavy rod set up. Ain't no marrying them together without mallory.
2900 sound about right from memory. I could check but I don't know if I have any pistons around.
What the heck piston are you looking at for that kind of money?

Thank you for looking, diamonds are $1,350 now , looking for a dome piston running a #88cc head, i can get a speed-pro dome but looking for a lighter set, where i live...... it is tuff to get anything done, machine work is the main thing,...................about ready to go to a stock steel crank. some pistons are 9.7 comp that does not do a thing for me. lol

Check ross,srp, or icon.

Icon/srp/wiseco/ diamond /ross ..................... I have checked and #1 are cheap heavy dome speed-pro all are flat tops, with no comp # numbers with a #88cc head , but the pricey dome pistons, my luck ,...... if anyone has a solution ( piston wise) please pm me,............

What about getting a lighter set of of H beam rods , the stock 6pak rods were a bad idea , hemi sized rods with little LY rod bolts. Also cut the heads down to a smaller chamber ?

I cut #100 thousand off the # 452 heads on another motor , that many be a route for me, i checked on rods Thursday and they are 809 grams for a steel one, don't know how much six-pack rods weight ,.......... since you can't get what you want you have too compromise , sounds like life !! lol

one random six pac rod
926gr
656 big
270 little

Now that is CRAZY ! but they work ,........thanks for the info,......................LOL

My friend bought a 66 Satellite racear. It ran decent. Decided to lash the valves. It had stamped steel rockers. So obviously a hydraulic cam. It also has a 6 pac balancer. Hew was told TRW /Speedpro type piston. Wiyh that balancer it has to have 6 pac rods as well. So it's all old school and heavy. Easily runs 11.40s and has dipped into the 11.30s. He runs it to about 6300. For the street I wouldn't worry about bob weight being heavy if you have the parts already.
Doug

I'm not knocking them. I just didn't think they would work with 2550.

You would need a piston/pin in the 790gr area. The stock piston/pin is somewhere in the 1000gr area as I can remember. I don't have a piston to weigh though.

You are correct , trw replacement pistons are 1000-1100 grams , piston/pin

I have a stock piston I’ll weigh. I know the pin is bigger and heavier than a stock one. I also have a 74 motor home 440 (never apart) that has 6pac rods, flat tops, steel crank and a regular balancer.

Do you guys think that if i buy a set of LIGHT Wiseco dome pistons /new crank bob weight (# 2550) / LY 440 rod in a +30 over block will it work in a street car with no balancing issues ? thanks for the input !!

Random ly rod
607gr big
239gr little



Stock bearing 58gr one set
rings 1/16-3/16th 62gr.

looks like you would need a piston/pin in the 916gr range.

looks like a ross 80762 with a standard pin (225g) would be real close.

On their website they list the pin as 158 but that has to be a typo, only the .990's are that light.

If that eagle crank is new and has never been balanced its probably not 2550 exactly or at the right place. There is a difference between "target bobweight 2550" and balanced to 2550.

Thanks I see your point, i got a card with the eagle crank with the weight, ???? you are right hoo know's ...................a bunch of trouble. with parts ! ............LOL

6 pac piston rod and pin
Piston 920
Rod 901
pin 251
440 stock pin 223
Stock 68 440 piston rod pin together 1932.5
6pac together 2071.2
68 piston 866 pin 223
Those 866 pistons came out of a 74 440 motor home block had 6 pac rods and steel crank and internally balanced, regular balancer.

I checked out the ross pistons #80762 ...like good, ..... i think with a 88cc head with a #40 felpro head gasket comp around 11.00 to 11.25 ...............i have not checked out the price yet. ?

Thank you i really needed that info cudaman 69 .......... is it the same with a HP block ???

Reg piston was not in a HP block but the combined one was. Slight difference in height between the 2, 68 being taller but neither as tall as the 6 pac. Remember the 69-1/2 6 pac had the regular pistons and LY rods, 70-71 had the high compression 4 valve notch pistons and big rods, externally balanced. I’m thinking the LY rod and lighter pin would get close to the regulars setup with internal balance, with a little metal removal in the piston (30 grams). That’s what I’m looking to do

You need the small and big end weights for the rod to calculate the bob weight.

2 big ends+ 2 con. bearing sets+ 1 little end+ 1 ring set+ 1 piston +1 pin + any locks for one piston+ (oil of choice usually 5/6 gr.)= bobweight.

Thank you sir, it has been a struggle matching parts ! all the stroker kits from Jegs ...........need balancing too ! *&^%$#@! it is hard when you have not bought the pistons yet,.........LOL LOL

Why can't some body made a affordable forged piston with a compression radio around 11.00 to 11.50 with a open chamber head in a stock block ? ..................... please i don't understand !

Because aftermarket choices are bleak to non existent for mopars... now it it were a chevy or smallblock ford ...

I got a set of trw forged designed for open chamber
.60 over they are close to 11 to 1 I never measured weight but I heard they are stock cast piston weight

Did you get your pistons from Jegs/summit/ or from there web-site ?

They are old stock 2295. I think they used to call them 6 pack pistons

There isa set on eBay for 60 bucks

Because that is a bad combination. Most customers want a combination that they can daily drive with pump gas. A modern closed chamber aluminum head with 10:1 compression using an off the shelf flat top piston makes great power and works with pump gas.

The TRW 6 Pack pistons have 4 notches and are identical to the stock ones in shape.

Yep, the 2295 are what gets termed "old trw dome tops".

The six pac is 2355

Thanks all the pistons for-sale i have seen are the low compression one's

What heads are you using ?

Then they’re not 6 pac pistons, should be 2.05 compression height at least.

Im using #452 heads for unleaded gas

Thanks cudaman, i seen a set of high conpression one's with a dome, i will remenber the piston hight for sure

Stock Iron or the Ebrock NHRA approved Alum ?

Im building the car like i woud have when i was #16 years old,...........mosty street...........strip car. 440 + 30 727 moved the rear back #11/2 inch's dana 60-4.10 some super stock tricks............LOL

the 2295 is probably the best option then.

Thanks brother, i will check them out, good luck this year with every thing !

Did you find a solution?

If you are interested in a complete short block that you could hear run before disassembly let me know.

I can send you a bunch of photos.

Thanks i will send you a PM..................Frank

How did you make out on the 2295 search , I just came across these .

pistons on facebook

I will check them out, the internet it not good here..............................to let you know my sister told me a could have her brand new steel crank 1967 .040 over short block.

Moving the rear end back is not good for traction, moving it forward is
It is way better to trim the front edge of the rear wheel wells than it is to move the rearend back towards the gas tank, that will increase tire spin

This is what I have for TRW/speed Pro pistons


Part# CH Weight Pin Wt CCs Deck Ht

L2266F 1.991 876 225 0 flat top .090

L2355F 2.061 872 225 -7cc .020

L2388F 1.926 819 225 0 flat top .155

L2295 2.029 817 250 13.1cc .140 dome .051

7025P 2.050 815 250 13.1cc .140 dome .051