Has anyone installed billet caps on a 440?

[TIMINATOR]

I have:
3 billet main cap kit
5 billet main caps kit
5 billet main caps with cross bolted center 3 cap kit.
Has anyone done the crossbolted caps?
How about experience with reliable street HP levels of the different caps and stock caps with ARP studs, which I will use with any caps I go with.
My goal is a street driven 72 Challenger with a 512 TFS headed solid roller motor to run 9 anything on the motor, and then stick My 300 HP plate on it and see what it runs.
The trans, rear, and chassis are done already, as is the roll bar. I'll make a trip to the track and see if I get booted for a 9 on the motor once it's sorted. Then put the plate on it and go to a different track and get booted for whatever it runs.
Thoughts on the caps?
Am I overthinking what it needs for caps?
I'll sell whatever caps I don't use, I just want all my options covered before it gets machined.
Big single plane manifold and HP 950 Holley.
Cam will be a Comp Cams solid roller about 272 or so at .050. Ported TFS 270 heads. Compression about 11.0 with Race tec or JE pistons
Billet liteweight 8 bolt aero crank.
Billet 7.1 rods.
Built 8 3/4 w axles, SS type springs (now), or Cal Tracs, relocated front spring perches.
Goal is a fun, limited street, occasional track car.
I'm thinking the 512 should do around 700 HP. Oh yeah, I will half fill the block too.
Thoughts, comments, or suggestions?
TIMINATOR

 

[Xcudame]

Although I haven't used anything other than stock main caps (everything has been less than 550hp), the cross bolted main caps (think Hemi) would make the most sense. The big block Mopar will live easily at 600hp and under. 800hp and above, there's likely to be catastrophic failure in the main cap/web area! You're in that gray area in-between, which is probably you're reason for concern. Some engine builders swear by aluminum main caps up to 800hp. Since you have a machine shop, I think the best option with the parts you already have is the cross bolted kit. I believe the Hemi block was good for 1000hp stock, so you should be safe.

Might want to consider a Dana 60 for the rear!

 

[TIMINATOR]

If I break the 8 3/4, I will upgrade then.
As an interesting side note about the 8 3/4, years ago I ran a Super Comp dragster, 427 brodix headed, [email protected] solid roller Chebbie, glide, 5500 stall with trans brake and 4.10 gears with a 1 3/4" pinion. It ran 8.40s @ 167, but I wanted a better 60 foot.
A friend had a set up punkin with 4.30s so I stuck my spool in it and ran it. He said that he thought it had a 742 pinion 1 3/4" gearset too.
After I had made 5 passes on it, then he tells me he knows it was a 741 REAL SMALL pinion gear from an old 6 cylinder van! I think those were 1 1/2" pinions....
Anyway, I ran it like that for 3 more Friday nite grudge races and 1 divisional, and never broke it! I put the new gears in my other punkin, and my friend sold the small pinion setup to a guy with a low 12 sec. Duster, who ran it for a few years and sold the car.
Had I not seen it, I would never have believed it!
My pal figured that I would get a pass or two and see how I liked the 4,30s before buying a new set. He said that if I knew they were a 741 set, I never would have tried them. He was right about that!
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[Xcudame]

I truly believe the stock factory 8 3/4 is tougher than any stock factory Phord 9 inch that everyone (non-Mopar) seems to rave about! And the 741 actually has a 1 3/8" pinion. So maybe you're experience backs up the strength of the 8 3/4!

 

[TIMINATOR]

I think the strength of the 9" has to do with the 3rd pinion bearing on the nose of the pinion, supporting the pinion from both sides with 3 bearings. The 8" has the same deal also. I have not broken any of those rearends, but I have seen a 9" years ago with the punkin case cracked at the pinions nose support. I prefer the 8 3/4" to the 9" because of the 8 3/4" has a smaller hypoid distance, allowing less of a HP loss, and the fact it is lighter overall than the 9".
The only gearset that I have broken was a 7 1/2" in my street/strip Regal with a 11 to 1 built 350 chebbie and 4.56 gears. With the 4.56s the pinion has only 9 teeth as I remember. The car ran 11.50s with the front wheels about a foot to 14" in the air.
With the 3500 convertor it ran for about a year before spontaneously removing ALL of the pinion teeth. I replaced the gears with a set of 4.11s (10 tooth pinion) and never hurt it again.
I am no fan of the Dana 60, as it too has a very deep (even more than a 9") hypoid distance, and has an even heavier deadweight than the 9".
I believe that quality bearings (Timken) and Richmond gears along with a perfect contact pattern are more important than type of rearend.
TIMINATOR

 

[6PKRTSE]

I have billet cross bolt main caps in my 528, but it is a Hemi street/strip 70 Challenger with no issues.

 

[TIMINATOR]

I have billet cross bolt main caps in my 528, but it is a Hemi street/strip 70 Challenger with no issues.

I'm talking about stock 440 2 bolt caps to aftermarket cross bolted caps, and what machining is required.

 

[Chryco Psycho]

I have done 2 bolt caps + a Main girdle , reliable as you can get ,
Yes you will break the 8 3/4 unless you have wheel spin in which case you are not gong into the 9s

 

[TIMINATOR]

How much HP have you consistently tun with the girdled block?
Thanks for the 8 3/4" info too.
It's worth more running than broken. 9" has now been put on my short list.
Thanks. TIMM

 

[Chryco Psycho]

460Ft lbs tq at the wheels on a Mustang dyno for over 14 years
I would do a Dana 60 over a 9"

 

[TIMINATOR]

What body?
What's it run, ET & MPH?
I appreciate the info, it will help give me a handle on my project and hopefully save me some grief, cash, and blind alleys.
TIMINATOR

 

[Chryco Psycho]

67 Coronet R/T , no track anywhere near just driven hard on the street

 

[mrmopar340]

460Ft lbs tq at the wheels on a Mustang dyno for over 14 years
I would do a Dana 60 over a 9"

Yeah my 340 does 444ft lbs. I think the 8 3/4 will be short lived if I play too hard.

 

[TIMINATOR]

Did a W2 340 about twelve years ago in a Duster with 4.30s I think. It is still running 10.80s@125 on the 8 3/4 with 10" slicks.
I have a few punkins and housings for 9".
I have an extra set of 3.90s for an 8 3/4" (1 3/4 stem) that was in my car with the 360. When I stuff the 9" in there, the complete 4.10 posi rear will be for sale. I need to list the stuff in the parts for sale, I have a bunch of stuff that I'm not using.
TIMINATOR

 

[mrmopar340]

Did a W2 340 about twelve years ago in a Duster with 4.30s I think. It is still running 10.80s@125 on the 8 3/4 with 10" slicks.
I have a few punkins and housings for 9".
I have an extra set of 3.90s for an 8 3/4" (1 3/4 stem) that was in my car with the 360. When I stuff the 9" in there, the complete 4.10 posi rear will be for sale. I need to list the stuff in the parts for sale, I have a bunch of stuff that I'm not using.
TIMINATOR

Mines an aluminum Edelbrock headed with a hughes cam and a six pak. I just dropped the 3.91's out and put 3.23's in. It puts 436 and 444 on the ground a 5k. I still need 2 more heat cycles on the gears to brek them in and then 500 miles till I gag on it and see how it runs.

 

[Tig]

460Ft lbs tq at the wheels on a Mustang dyno for over 14 years
I would do a Dana 60 over a 9"

I have a Dana 60, I had real problems finding "pro" (soft tempered) gears numerically lower than 4:10. I needed 3.73. I rang a few manufacturers Strange, Richmond, Williams, Eaton Etc and was told they are made in Italy and they had stopped making pro gears in ratios below 4:10. Numerically above 4:10 were being produced but since they are reducing "aftermarket support" due to lack of demand, only in limited numbers.
In the end I had to settle for "street" (hard and therefore brittle) gears, they are a ticking timebomb. I'll be installing a 9" derived rear soon as they have plenty of available pro gear ratio's. Below is a pic of some 4:10 street gears, my advice would be to visually inspect them regularly. Just something the OP should be aware of.

 

[TIMINATOR]

Who set up those gears? From what I can see it looks like the wear pattern is heal drive and high on the teeth like the backlash may have been loose from bearing wear or not enough carrier bearing preload. I have run G body's with the stock 7 1/2" 10 bolt rears in the eleven and one in the 10.90 range with standard Richmonds and no issues.
But then again I run more pinion and side bearing preload than specified and synthetic gear oil.
You have to run a LOT of posi spring load with synthetic oil though. It decreases the posi action, but it's great for the gears and is worth a few hundredths and a bit of MPH too.
TIMINATOR