632ci dart tall deck pros and cons?

Discussion in 'Engine Topic' started by 70ssrat, Mar 28, 2007.

  1. 70ssrat

    70ssrat New Member

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    Jan 13, 2007
    :) I just recieved my shortblock and pro-1 heads from dynoflo. It is a Dart big-M block has forged JE 4.600 flat top pistons @10.5-1 with the pro-1 heads, Eagle 4340 4.75 stroke crank and esp rods. It is going in a 70rs/ss which at this point leans more towards pro-touring than pro-street. I am redoing the stock th400 and regearing and putting axels in the 12bolt.
    Do the 4.75 strokers have any particular issues that I should be watchful of?
    Anyone have tips on installing tall decks in 2nd gens? Also has anyone else here done business with Dynoflo and how was your experience.

    Thanks,
    70ssrat
     
  2. DirtyScotty

    DirtyScotty Veteran Member

    Off the top of my head you may want to run a hydroboost brake system instead of the booster/mastercylinder combo. I would imagine the valve covers would hit the master and maybe booster.
     
  3. rustbucket79

    rustbucket79 Veteran Member

    Quote: Do the 4.75 strokers have any particular issues that I should be watchful of?

    Other than limiting the engine to a reasonable redline and needing controlling interest in a tire company, no issues as long as it was built correctly.
     
  4. camcojb

    camcojb Veteran Member Lifetime Gold Member

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    Jan 10, 2000
    Wilton, Ca. USA
    what hood do you plan on running, because hood clearance for a proper manifold and air filter size will be very interesting.

    Jody
     
  5. PhilM

    PhilM Veteran Member

    1,274
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    Aug 30, 1999
    Pac NW

    You should have no problem with that DYNOFLO short block. I have never heard of anyone having problems with them personally.

    Having done the TD before here is what I had to do.
    1. Buy a 4" cowl hood to clear the super vic intake, carb and 3" air cleaner.
    2. Use the SBC towers and SBC motor mounts.
    3. Bend over and get ready to spend about 1k on a set of headers. I dont know where you are located, but it would be worth the trip to send the car to Lemmons and have a set done. You will need a min od 2 1/8" primarys. No hooker or hedman will fit!!!
    4. The brake booster out of a 3rd gen iroc will fit if you use fabricated valve covers. Tall valve covers will not clear.
    5. Use small block long style pulleys on the crank,W/P and power steering.

    Thats what I did in its street driven trim.

    Personally, I would buy a motor from them. One of thier guys, dont remember his name helped me change out some main bearings at a PSCA race in Vegas in my camaro a few years ago. This was on a 920 hp+ n/a 350. He knew what was going on and I plugged him for info along the way. No BS was spelled out at any time by him. I would trust him and I know of others that have bought from him and are 100% happy.

    Remember this as well. A cam that is big in a 454 will be very small in that beast you have. Good luck on trying to get that thing to hook...:D
     
  6. kik_start

    kik_start BANNED

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    Sep 3, 2006
    gone crazy
    632ci street motor! Hummmmm, how big of a trailer you gonna pull behind for spare tires?
     
  7. 70ssrat

    70ssrat New Member

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    Jan 13, 2007
    This motor overkill started when I decided to replace the 402 in my camaro and build a 496 stroker. As I looked into putting it together the cost of prepping the 454 block and stroker kit was only going to be about $900.00 less than a brand new after market shortblock that is superior and could hold much more cubic inches. After deciding to build a 572 Scot at dynoflo said he could build a 632 with 60 more ci and 3/4" more stroke for less than $400.00 more. I have always been a too much is not enough kind of guy so here I am trying to shoehorn a mountain motor into a street camaro:crazy:
    O.K. as far as hoods go for some reason I have always had a soft spot for the cheesy L88 fiberglass hoods but they only give 3 1/2" additional clearance so I will probably go with the 4" cowl.
    On the brake booster Im in a wait and see mode but I am running tall fabricated valve covers.
    So small block motor mounts will lower the motor into the subframe?
    I am still in retail sticker shock over the header issue.
    Also finding an off the shelf oil pan for a 4 3/4" stroke that fits a 2nd gen has been frustrating. Also this is a factory A/C car and was wondering if there is an aftermarket system that the condensor would clear the valve covers.
    I am looking at a doug herbert hydraulic roller: 242/246 dur @50, 642/663 lift, 112 L.C. does that sound smallish for this displacement?
    Thanks for the responses,
    70ssrat
     
  8. kik_start

    kik_start BANNED

    3,302
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    Sep 3, 2006
    gone crazy
    I have a cam close to that in my 496...
     
  9. MyBoTy

    MyBoTy Veteran Member

    1,535
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    Feb 9, 2002
    Lubbock, Texas USA
    There's a guy at the Chevelles site that's putting one in a '68 - '72 Chevelle. He's having fits - the crossmember had to be cut, among other things. Those big stroke engines don't work well with door slammers, too much clearance issues. I talked a long time with a lot of engine builders and they all agreed that the 555/565 is pretty much the optimum for a street engine. Short deck, conventional heads (your 632 is probably going to run out of air before you get to 6K) and off the shelf parts that will make way more power than you can ever hope to hook. According to the guy on the Chevelles site, your fun is just beginning with pan and header issues.
    Good luck, hope it works out for you with minimum headaches.
    By the way, what intake/carb are you going to use to feed that beast?
     
  10. PhilM

    PhilM Veteran Member

    1,274
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    Aug 30, 1999
    Pac NW
    I dont think that that hood will work. If I remember correctly, it tapers back towards the cowl.

    Your oil pan will probably cost no less than 600 bones. I has a Jeff Johnson fabed ban and i was only running a 4 1/12" arm. The small block mounts were used because that is what I had. Looking at a set of BBC mounts showed me there was no way the pan would have worked.

    If you are going to run a small cam like that you may want to just use a set of hookers and see if you can make them fit. I found my invoice for my headers and they were $1800 coated. The will not fit inside the frame rails, so be prepared.

    Your cam. This really should not have been an afterthought. It seems to me like your heads already have solid roller springs set up on them. I personally would do a solid roller. Thats me though.

    If your compression ht is around 1.087 which it probably is, you wont be able to have a long lived street motor. That is that much more reason for a solid.

    I understand about the bigger is better thing. I got cured of that when a 377 outran my 540. Now I am the other way, but thats me.

    I have heard thats its sometimes necesssary to move the motor back about 1/2 inch for the pan to clear, but then you have major header issues.
     

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