When to use 48 degree block

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cpearce

cpearce

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Hello all,

Over the next few years my engine builder and I will be building a race only engine looking to run low 10's in a 73 Duster. The engine will be using W2 or Indy 360-2 heads and a 3.58" crank with 340 mains. I have various intakes including a tunnel ram to try and plan on a solid roller cam.

My engine builder has kindly offered to swap me a 48 degree block for my 59 degree R3 block if I wish. I understand this will require a specific cam, headers, timing cover, and also the modification of the intake manifolds. Going this route requires a bunch of one off stuff I will need to buy and added expense. Benefits of course are lighter pistons and improved valvetrain geometry.

My question is this, at what point is the 48 degree block a real advantage over 59? What RPM can one spin reliably on a 59 degree 1/4 mile drag engine with good parts. Is it required for what I am tryimg to do? All of my stuff and associated parts are 59 degree at this point providing ease of parts swapping and interchange. I am not opposed to the 48 degree change, I would just like to make a very well informed decision. Any information you folks can provide me about this switch in an A body will be most appreciated. ie. Exhaust fitment, etc.

Thanks in advance for input.
 
Everything you said seems to be tremendous overkill for aspirations of low 10's 73 Duster? Seems to me a well prepped 360 with some decent heads would get you there without all that Overkill and expense?
 
My .02
The 59 degree block will handle all you throw at it. The 600 hp limit fear is just a myth. As long as the cylinder walls are thick I would not fear it.

The w2 or 360-2 Will make power I would go indy 360-1. The 360-1 heads are similar to w5s with the square intake port.

The 48 degree block is great but all the extras you will need will get expensive fast. As far as I understand the 48 degree block is discontinued so all the extra parts to make it work are drying up.
If going 48 degree I would look at w8s or w9s
I know there was a shortage of 48 degree cam cores so you may want to dig around. Timing covers are another issue
Also the 48 blocks have tall decks and short deck which also makes things different with the timing covers.
I am sure things are available but the extras are hard to find.
Almost easier to find an ex NASCAR r5 or r6 block with the p heads.

But this is what info I have gathered over the last year
 
Since parts have dried up & are no longer even being looked at for re making them again, the already expensive endeavor is going to escalate IMO.
I would love a MP race block BUT not a short deck 48* larger cam journal block. That! Would out strip my wallet for starters, considering the host of odd parts but also there availability & verity.
 
rumblefish360 said:
Since parts have dried up & are no longer even being looked at for re making them again, the already expensive endeavor is going to escalate IMO.
I would love a MP race block BUT not a short deck 48* larger cam journal block. That! Would out strip my wallet for starters, considering the host of odd parts but also there availability & verity.
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Great points, thanks
 
j par said:
Everything you said seems to be tremendous overkill for aspirations of low 10's 73 Duster? Seems to me a well prepped 360 with some decent heads would get you there without all that Overkill and expense?
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Even like 10.01, lol? Yes I agree I often venture into overkill. I do however believe in doing things right the first time as it has proven to be the most economical in the long run. Good parts also allow for upgrades in the future. Again, I do appreciate your response. What would be your recipe knowing what I have and what Im after?
 
cpearce said:
Great points, thanks
Click to expand...
Your welcome. Just my view. At this point in time for myself, I have been considering the best four letter word I the world ..... HEMI

IMO, be it the current small block for the street machine for yourself or what I would like to do, a Gen II & start with a KB block and go from there.

It’s the most bad *** foundation to start with.
 
rumblefish360 said:
Oh, what does your ‘73 weigh in at?
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The purchase of the car happens this spring, car is and has been a stock eliminator car since new. Currently runs 11.0's with a low comp small valve 340. So on that point it is fair to assume the car is figured out. As far as weight I'm going to guess low 3000's. I'm going to run with that setup for next few years. Im entering myself into uncharted territory!!!!!! Lol. Im eagerly anticpitating it sharing space in my garage with my Dart.
 
Hummmm, you know that is actually a good question and my answer is maybe it is figured out. But figured out for what it is doing now, not what you have planned. Is it a far different animal? IDK.
Low 11’s and low 10’s are not the same (IMO at least) not really the same as 16’s to 15’s. LMAO!!!
I think it’ll be fun without a crazy effort suspension wise.
 
You run the 48* stuff when you can get it. ET and HP mean nothing. The 59* lifter bank angle was left over from the poly head stuff. Valve train geometry is critical. We lived with th 59* crap because it's what we had, and I didn't have the balls to cut the lifter valley out and correct it, but some guys did it.


You'd be nuttier than a jar of goobers if this guy is willing to trade you into 48* stuff. Hell, I'd do it in a heart beat.
 
yellow rose said:
You run the 48* stuff when you can get it. ET and HP mean nothing. The 59* lifter bank angle was left over from the poly head stuff. Valve train geometry is critical. We lived with th 59* crap because it's what we had, and I didn't have the balls to cut the lifter valley out and correct it, but some guys did it.


You'd be nuttier than a jar of goobers if this guy is willing to trade you into 48* stuff. Hell, I'd do it in a heart beat.
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Thanks Yellow Rose,

The trade would be my brand new 59 degree R3 block for his new 48 degree 9.2 block. Afterward I would have to buy rest of the things to go with it.
 
cpearce said:
Thanks Yellow Rose,

The trade would be my brand new 59 degree R3 block for his new 48 degree 9.2 block. Afterward I would have to buy rest of the things to go with it.
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I don't mind the 9.2 deck if you keep the stroke under 3.80. Does he have the timing cover and all that you can buy from him or do you have to find it?

This is what sucks about dealing with Chrysler. They don't care about anything and let **** just hang. Of course, the idiotic NHRA/Pro Stock Truck deal didn't help with that.

Think of what we would have if Chrysler had stayed in ASScar and NHRA didn't kill PST.
 
yellow rose said:
I don't mind the 9.2 deck if you keep the stroke under 3.80. Does he have the timing cover and all that you can buy from him or do you have to find it?

This is what sucks about dealing with Chrysler. They don't care about anything and let **** just hang. Of course, the idiotic NHRA/Pro Stock Truck deal didn't help with that.

Think of what we would have if Chrysler had stayed in ASScar and NHRA didn't kill PST.
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Stroke is 3.58, another member on FABO has a new timing cover. I understand we can machine my intakes down. I would have to source out a UGL cam core. I'm not sure if headers change or other unique items I may need to make the change.
 
cpearce said:
Stroke is 3.58, another member on FABO has a new timing cover. I understand we can machine my intakes down. I would have to source out a UGL cam core. I'm not sure if headers change or other unique items I may need to make the change.
Click to expand...

Well hell, you're pretty much golden. You will need 48* heads but I know some modified the 59* heads to work. Or maybe it was the other way around.
 
I know for fact that 48* heads can work on a stock 59* block. Going the other way should be possible. It could be a lot of clearancing for the pushrods.

Can you get an intake for the 48* block. That’s my stopping stone. I’m not welding one up. Or pay the price of having it done for me. Although the cost of the short deck race W2 is ridiculous. If you can find a single plane short deck intake.
 
cpearce said:
Even like 10.01, lol? Yes I agree I often venture into overkill. I do however believe in doing things right the first time as it has proven to be the most economical in the long run. Good parts also allow for upgrades in the future. Again, I do appreciate your response. What would be your recipe knowing what I have and what Im after?
Click to expand...
Yes Overkill is good LOL and way out of my realm talking about are three blocks and stuff like that for sure. It just seems I've seen low tens out of stuff that wasn't so expensive. And if I wanted to do something in the low 10 seconds consistently I would think about a stroked big block. Now I'm definitely a small block guy for sure and I don't really like the idea of a big block on the street but if it was a dedicated strip car just looking to do low 10s I would definitely consider it. I also have a 73 duster just a stroked 360 mid 11's it should go faster but...
Bottom line is however you like to enjoy the shoppie is just the way I like it to that way we're both happy! I know when I'm talking out of my realm but it just seemed as a lot of stuff when I've seen guys do that kind of time without talking are three blocks and things like that which are again way over my head now, but who knows in the future. Again thank you for asking.
 
cpearce said:
Stroke is 3.58, another member on FABO has a new timing cover. I understand we can machine my intakes down. I would have to source out a UGL cam core. I'm not sure if headers change or other unique items I may need to make the change.
Click to expand...

Chris, you should get in touch with Brett Miller--he is a great resource on this. I can put you in touch. J.Rob
 
59 degrees seem to work ok for most Folks!
We have 360 strokers running into the nines these days...
Mopar is expensive which ever way you go.
The cheapest way to go fast is with sawsall and sharp chisel lol...:rofl:
 
I wouldn't consider trading for a low deck unless he had all the necessary components to go with it. I'm running a 434" 59° R1 in my Dart, it has ran 6.40 at 109 in the 1/8 at 3350# on pump 93. it will run in the .30's and should run low 10's in the 1/4.
 
joey arrington in martinsville might have some this one off stuff left over from when mopars nascar effort was based there!
 
No way i would make that swap
And if it was me i would use a stroker crank to knock rpm’s down. Especially in a bracket deal you want to run 10 flat with
I have about the same project in the works but think i can do it with the new trick flow heads and intake
As mentioned an Indy head will get you where you want too
 
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