Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Big Block Heads and Block work. . .

Discussion in 'The Garage' started by BowtieRed, Jun 18, 2003.

  1. BowtieRed

    BowtieRed 1/2 ton status Author

    Joined:
    Dec 31, 2002
    Posts:
    1,776
    Likes Received:
    0
    Location:
    Winston-Salem, NC
    I have decided 100%, for sure, I am going to buy a used block, probably a 454 block- and going to build it up and drop it in the blazer. My question now is- what heads to look for and how much can i bore it? What kind of max stroke can i get without clearancing? What is the biggest CI i can pull out of it safely and not have to pay for clearancing? Any certain #s i should look for? a 4-bolt main is best right? i don't know big blocks all the well yet, but hopefully next year i'll have one sitting under the hood and the whole neighborhood will be well aquainted with a 3" straight piped BBC /forums/images/graemlins/grin.gif

    note- i'm looking to spend $5-700 on some new or slightly used aluminum heads, then port and polish them.
     
  2. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    I don't know big blocks either but i do know 500-700 for heads plural is very hopeful. Maybe a head.
     
  3. Don

    Don 1/2 ton status

    Joined:
    May 30, 2002
    Posts:
    1,778
    Likes Received:
    0
    Location:
    Spokane Washington
    I don't have the "casting number list" avaialable here for head's, block's etc. got to the "net and type in: big block chevy casting number's, and a whole slew of different page's will; show up.



    I do know that You can safely bore it too, .060 over that's what mine is, a 468 now, with a stroker, I have no idea what the largest is, or how much of an overbore, it will handle. /forums/images/graemlins/grin.gif

    or got ot www.mortech.com it is a casting number page for big block's.
     
  4. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    5-700 is the price for like 1 aluminum head lol. Double that for new. Slightly used would only knock 100 or 200 off the price. Oval port heads and torque heads, Rectangles are for racing engines, a good set of factory iron heads are the ones that end in the 049 casting #'s. They are the best performing factory oval port heads ever. Im tryin to get a set off ebay, but the guy is being a bastard, if i dont get em, i might get the world products oval ports. Again, for that price getting a set of irons is the only hope.
     
  5. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    Yes 4 bolt is the best, im going to go .060 over, ive heard of people going .125 over but thats definately pushing it. Im going to a 4.25" stroke, to make it a 496, but you will barely hafta clearance the block. Machine shop says maybe 45mins to an hr wortha work.
     
  6. Don

    Don 1/2 ton status

    Joined:
    May 30, 2002
    Posts:
    1,778
    Likes Received:
    0
    Location:
    Spokane Washington
    There are other casting number head's which are very close to the 049 head's I have a set on Mine, but I'd have to pull a valve cover, to see the damn number.

    With bigger exhaust valve's, they flow like gangbuster's, and have excellant torque, throughout the powerband.
     
  7. Rolled

    Rolled 1/2 ton status

    Joined:
    Jun 16, 2002
    Posts:
    683
    Likes Received:
    0
    Location:
    Anchorage, Alaska
    Get yourself a 2 bolt then buy some aftermarket splayed main caps. The splayed 4 bolt caps are much stronger than the stock 4 bolt.

    I have the largest (that I know of) collection of casting numbers if you need a hand identifying anything. I have most of it compiled into a data base so its easy to look stuff up.


    Good luck and extra good luck finding those aluminum heads /forums/images/graemlins/wink.gif
     
  8. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    i believe 781 are the ones like the 049's, but for some reason they dont seem to be as common, atleast around here...
     
  9. Don

    Don 1/2 ton status

    Joined:
    May 30, 2002
    Posts:
    1,778
    Likes Received:
    0
    Location:
    Spokane Washington
    781's ring a bell in my head, I think they are the one's! /forums/images/graemlins/grin.gif Add some larger exh. valve's and have the machine shop,hog out the bowl's, [they have a tool called a bowl hog] it make's porting, cleaning the bowl's up, alot faster. /forums/images/graemlins/cool.gif

    Then add a good 3 or 4 angle seat's, and your ready to Rock! /forums/images/graemlins/grin.gif
     
  10. BowtieRed

    BowtieRed 1/2 ton status Author

    Joined:
    Dec 31, 2002
    Posts:
    1,776
    Likes Received:
    0
    Location:
    Winston-Salem, NC
    ok, well maybe i'll get some stock ones with 049- think those could pump 600hp with some porting and new rockers etc? could i find a good set of LS6 heads for a decent price? i know i have a lot of questions, but i really want to make this thing haul!
    thanks,
    red

    www.speedomotive.com has some kits working it out to close to 572CI. . .but i was thniking 496 would be good.
     
  11. thatK30guy

    thatK30guy 1 ton status Premium Member

    Joined:
    Jan 12, 2001
    Posts:
    32,076
    Likes Received:
    55
    Location:
    .
    Why would you want 600 hp? Thats a lot you know. More than you would need for any type of off roading especially rock crawling.

    Generally, you will get higher hp's with rectangle port heads but if I were you, I would concentrate more on torque and use the more common oval port heads instead. Just build a mild engine that will be capable of doing 400-500 hp. With that in mind, you should have a torque monster that puts out over 500 ft. lbs. /forums/images/graemlins/wink.gif /forums/images/graemlins/thumb.gif
     
  12. Don

    Don 1/2 ton status

    Joined:
    May 30, 2002
    Posts:
    1,778
    Likes Received:
    0
    Location:
    Spokane Washington
    No You don't want Rectangle port head's, only good for High RPM use, settle on Large oval Port Head's, not the small peanut port's, but Large Oval, circa, mid 70's, chevelle's, monte's, pickup's, K30 Guy is correct, it easy to pull 500 ft. lbs. of torque out of Oval port head's, Build it for Torque, and horsepower just is a side benefit. /forums/images/graemlins/grin.gif
     
  13. BowtieRed

    BowtieRed 1/2 ton status Author

    Joined:
    Dec 31, 2002
    Posts:
    1,776
    Likes Received:
    0
    Location:
    Winston-Salem, NC
    YOU DON'T UNDERSTAND!!!!! ahhhhh
    I do mud runs- i need horsepower. i do now rockcrawl. the only rocks in NC are on the beach, they are crushed up and called sand! i have got to spin them tires fast! yes, i need torque too, but torque with come with hp- i am so obsessed with HP i REALLY should drag race. i need a muscle car- but i LOVE running in the mud so i want something powerful enough to do both /forums/images/graemlins/rotfl.gif

    in my mind i need 600hp- so could stock heads with a little porting do it? /forums/images/graemlins/grin.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif
     
  14. jjlaughner

    jjlaughner 3/4 ton status

    Joined:
    Jan 12, 2001
    Posts:
    7,406
    Likes Received:
    0
    Location:
    Indiana
    [ QUOTE ]
    note- i'm looking to spend $5-700 on some new or slightly used aluminum heads, then port and polish them.


    [/ QUOTE ]

    A buddy of mine has a backup set of 454 heads for his drag van, he joked about selling them to pay for the supercharger repairs. PM me and I'll send you his email address if your interested
     
  15. Don

    Don 1/2 ton status

    Joined:
    May 30, 2002
    Posts:
    1,778
    Likes Received:
    0
    Location:
    Spokane Washington
    Now We understand! Mudrun's o.k. You do need High Rpm power, and torque too, Grassahoppa, you need to be clearer on what You mean. /forums/images/graemlins/eek.gif
     
  16. BowtieRed

    BowtieRed 1/2 ton status Author

    Joined:
    Dec 31, 2002
    Posts:
    1,776
    Likes Received:
    0
    Location:
    Winston-Salem, NC
    lol- i just end up saying that in every thread where i mention horsepower, i DO need start mentioning that earlier /forums/images/graemlins/rotfl.gif
     
  17. eldon519

    eldon519 1/2 ton status

    Joined:
    May 27, 2002
    Posts:
    161
    Likes Received:
    0
    Location:
    Kennesaw, Georgia
    [ QUOTE ]
    781's ring a bell in my head, I think they are the one's! /forums/images/graemlins/grin.gif Add some larger exh. valve's and have the machine shop,hog out the bowl's, [they have a tool called a bowl hog] it make's porting, cleaning the bowl's up, alot faster. /forums/images/graemlins/cool.gif

    Then add a good 3 or 4 angle seat's, and your ready to Rock! /forums/images/graemlins/grin.gif

    [/ QUOTE ]
    How much do you think that work would cost to have done including parts? Also, do you know how big the combustion chambers are on these heads?
     
  18. Don

    Don 1/2 ton status

    Joined:
    May 30, 2002
    Posts:
    1,778
    Likes Received:
    0
    Location:
    Spokane Washington
    I had Everything done to my head's, I think all the work was around $280.00, I bought bigger valve's from Summit. Valve's were around $100.00
    So, 280.00 and 100.00 = 380.00

    Magnaflux Head's
    Sandblast Head's
    Mill Head's
    Add Bronze Guide's
    Bowl Hog Bowl's
    3 angle valve seat's
    increase exh. valve seat's diameter
     
  19. TONYP

    TONYP 1/2 ton status

    Joined:
    Aug 13, 2002
    Posts:
    2,116
    Likes Received:
    0
    Location:
    so cal
    I've got a set of alum heads that are made for HP...titanium valves and valve keepers, ported and polished...I had them in a jet boat and ran 8300rpms... /forums/images/graemlins/thumb.gif
     
  20. Rolled

    Rolled 1/2 ton status

    Joined:
    Jun 16, 2002
    Posts:
    683
    Likes Received:
    0
    Location:
    Anchorage, Alaska
    [ QUOTE ]
    Just build a mild engine that will be capable of doing 400-500 hp.

    [/ QUOTE ]

    MILD /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif

    Nothing mild about that /forums/images/graemlins/smile.gif
     

Share This Page