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Chevy 305 Vortec Heads 520 059 casting questions

Discussion in 'Engine / Swaps etc.' started by RKRUZIN, Dec 8, 2012.

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  1. RKRUZIN

    RKRUZIN Not-quite-so-new-guy

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    I was looking at pulling my heads because of some sealing issues and thought I would just bolt on a new set of heads while I was at it. I know I would have to change my intake manifold and valve covers to a centerbolt style but I was wondering what else do I need to change? I have a 1984 Chevy 305 block

    do I need to change pushrod length, lifters, what rocker arm do I need self centering? regular stamped steel?

    looking at these

    http://shop.advanceautoparts.com/buy/pr ... fragment-2

    or cheaper yet

    http://www.mechanicsselectcylinderheads ... nder-head/
     
  2. Mikes84GP

    Mikes84GP Not-quite-so-new-guy

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    I completed this swap a few months ago with the vortec 520 heads. Your pushrod length will remain the same, and the rockers need to be self-centering. You can go with the factory stamped steel or aftermarket roller as long as they are self-centering. When you swap to the vortec intake make sure you grab new intake bolts. They are 5/16-18 x 1 3/4 if you'd rather pick them up from a hardware store. I believe I used the Fel Pro 1255 gaskets as my intake had low torque requirements (12 ft. lbs.)

    Here's what I found on ebay- http://www.ebay.com/itm/305-vortec-...Parts_Accessories&hash=item19d7443524&vxp=mtr

    The heads already have the rockers so that would be one less thing to worry about. I don't know about the 307 casting number given, couldn't seem to find that number online.
     
  3. RKRUZIN

    RKRUZIN Not-quite-so-new-guy

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    very helpfull! did you notice any noticeable change in performance? was it worth it? did you go with used heads or reman heads?

    I've got sealed power rp3093 push rods listed 7.794" OAL does this look correct?
     
  4. Mikes84GP

    Mikes84GP Not-quite-so-new-guy

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    I ran some used heads I found off ebay. In my case, it had the rockers and valve covers included, and I only needed valve cover gaskets for them.

    That pushrod you listed will work. It had 2 bent pushrods when I swapped heads, and I replaced them all with sealed power RP5000RK pushrods.

    I can't really give you a fair comparison in terms of performance gains from the swap because my car was running so crappy before the swap. I purchased my car with a blown headgasket and a couple bent pushrods, so of course I noticed a tremendous increase in performance.

    Are you replacing the cam at the same time? If so, what cam did you have in mind?
     
  5. RKRUZIN

    RKRUZIN Not-quite-so-new-guy

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    I was looking at comp cams XE256H for a cam...I'm not sure how much I want to do because I was going to just do a crate engine in a year or so..I have blow by and smoke and it's using oil after it's warmed up..sounds like rings to me..or possibly valve guides/ seals maybe..not sure what move I should make..I am already doing 8.5 inch GM axle and full suspension upgrade as well as wheels and tires and a 700r4 swap while I've got her in dry dock not sure what I should do..
     
  6. DRIVEN

    DRIVEN Comic Book Super Hero

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    Sounds pretty tired. If you're doing a crate engine soon I wouldn't recommend doing anything to your present engine. Fresh heads will likely make it smoke more if the rings are that bad already.
     
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