1971 350 Header Install

Discussion in 'Small Block Tech' started by knucklebusted, Mar 27, 2019.

  1. knucklebusted

    knucklebusted Well-Known Member

    I'm getting ready to try pulling the 1971 original manifolds off the 91K mile original motor in my 71 GS 350 4 speed.

    First, will the standard Hookers work on a 350 4 speed car?

    Second, pray for me with the gods of rust and corrosion to let me please get all 14 bolts out with no breaks.

    Third, I've got a MAP gas torch at the read. I have never tried the paraffin wax variant. Is it really that good?

    I hear the secret is to heat up the area of the head around the bolt, maybe tap it with a hammer and try easing it out that way.

    I've started soaking the bolts in kroil and the back sides of the ones that actually are through holes. The ends and center bottom are not through holes.

    Any secrets to pulling 48 year old bolts out of heads?

    Assuming it all goes to crap, would I be better off pulling the motor or pulling the heads?

    Anyone got big valve 350 heads for sale at a reasonable price? I'm not going to put aluminum ones on this car and I'm probably an idiot for putting headers on it but I've done worse.
     
  2. johnriv67

    johnriv67 Well-Known Member

    Prepare to pull the heads at worst, I pulled the whole engine for my shorty headers, as well as rebuilding the 430, but no way would I try taking those bolts off in the car
     
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  3. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    Map torch will not get hot enough to do anything. Need oxy/acetylene. It will only help you on the bolts that go into the ears by the spark plugs. Get that ear red hot then work the bolts back and forth unscrewing it a little farther each time. DO NOT HEAT THE bolt head directly.
    If the bolt heads are rusted down and the 9/16" socket is not very tight fitting try driving a smaller metric socket onto the bolt head. 14MM or even 13mm if it really rusted. Good luck.
     
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  4. alec296

    alec296 i need another buick

    Use only 6 point sockets. Might as well think about having big valves put in incase you have to pull a head for broken bolts.
    Mill the heads for a bump in compression too.
    Headers will lean out carb, may want to jet up .
     
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  5. 72gs4spd

    72gs4spd Well-Known Member

    I read the acetone and atf mixed 50/50 works real good. I use it along with PB Blaster when I did mine only broke one bolt. It was in the front and was able to dril it out with a right angle drill. Lucky I guess.
     
  6. Entropy11

    Entropy11 Well-Known Member

    A few of my own tips for what they're worth... just pulled another set tonight.

    If your car is functional and on the road, hit the bolts with penetrating fluid and go for a good ride. Hit them again when you get home. If you're not in a hurry, do this as many times as possible. Heating/cooling cycles with penetrant.

    I've tried Kroil, 50/50 ATF/Acetone, and several others. I prefer Seafoam Deep Creep (not the easiest to find, but I think it works the best). I alternate that with 50/50 if I'm really worried.

    6 point socket and *not* the longest ratchet/breaker bar you can find. I can get a better "feel" with a standard length ratchet. You want to feel difference between the bolt twisting vs backing out. Hop around to different bolts when you first start. Find an easy one to help you get the feel. Get it to barely move (loosen) and then snug it back a little. Remove the entire bolt that way. Even if it seems easy, keep going back/forth till it's out. I've snapped the odd one that I swore was "loose" only to have it snap about 50% out. If you don't have a good feeling about one coming all the way out, move it a little, add more penetrant, and come back tomorrow.

    Sorry for the long winded response... lol
    If you have a buddy with an O/A torch I'd make that step 1, but still take your time.

    Edit: My apologies if this post came off as "preachy" or "do this/don't do that". Just posting what works for me personally and spreading some of those ideas. Thanks to forums like these I've received tips that helped make my work easier. Best of luck.
     
    Last edited: Mar 30, 2019
    blyons79 and knucklebusted like this.
  7. patwhac

    patwhac Well-Known Member

    I just did this like 4 hours ago, granted my engine is on a stand. All I did was spray it down with Gibbs and give each bolt a few good smacks with a hammer. Used a breaker bar (now I know I shouldn't have :p) and did the loosen/tighten technique and all of em came out easy. When I tried to do this in the car a few months ago (different engine) I did break one bolt, but I wasn't able to get a hammer in there to smack em. So I think the impact force really makes a difference.

    Hope it goes well!
     
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  8. 12lives

    12lives Control the controllable, let the rest go

    Patrick - are you saying you hit the breaker bar with the hammer?
     
  9. alec296

    alec296 i need another buick

    Hit the head of the bolt without the socket on it as if it was a nail.
     
    Entropy11 likes this.
  10. patwhac

    patwhac Well-Known Member

    Exactly what Alec said, hit the bolt head nice and square. You can use a flat punch (or old bolt) in between the hammer and bolt head if you're worried about hitting the exhaust manifold. Don't be afraid to really smack em, 3 or 4 times each worked for me!

    Also a slide hammer may be of use if there is a particular bolt that you can't get to with a regular hammer, but it does get tight down there so it may be more of a pain than it's worth if you have to move a bunch of stuff out of the way to slide hammer a bolt.

    Your engine is still in the car correct?
     
  11. knucklebusted

    knucklebusted Well-Known Member

    Yes, motor still in car. I'm about to make a deal for a whole short block/rotating assembly and a set of big valve heads in case anything goes wrong. I like being prepared for a worst case scenario.
     
  12. patwhac

    patwhac Well-Known Member

    Always best to be prepared! It took me a year to find a used 350 that ran and was on a run stand when I looked at it, and made good compression. So I ended up paying a bit more than I would have a core engine. Out of curiosity, what are you paying for a core 350 in your area?
     
  13. knucklebusted

    knucklebusted Well-Known Member

    I've only been a 350 guy again for the last few years. Had my Stage 1 GS for almost 40 years now. I haven't bought a core motor in a very long time. I gave $100 for a 455 block, 2 sets of heads, exhaust manifolds and some intakes. The engine/heads I'm negotiating is from a board member here that sold his car after he had the heads milled, big valved and some home porting.

    You know how things get away from you, right? I planned on just putting headers on the GS 350 4 speed car but the stuck bolts are prompting me to consider alternatives. If the manifold bolts break, off come the heads. While the heads are off, might as well freshen them or swap them. Big valves are a bonus. It would be a shame to let those big valves wheeze on a stock cam and low compression. Might as well see what a cam costs. Heck, I'm basically down to a short block any way, might as well freshen and regasket it or build a spare one and swap it all as a unit and be done with it.

    So, I started with wanting new duals and headers and I'm now negotiating for a block and heads for a hipo 350 swap.

    It's a sickness, easily cured with time and money but not in that order.
     
  14. patwhac

    patwhac Well-Known Member

    Haha maybe you secretly want the bolts to break so you have an excuse to upgrade your 350! :D Sometimes we can be our own worst enemy!

    It can be hard to figure out what will give us the best bang for the buck in the long run, but if your engine runs well now I would try and drive it some more before you dive into upgrades. Or put one of your spare 350s on an engine stand and get is as ready as possible, then do a quick engine swap and you don't have a lot of down time. That would have been me but the 350 in my car blew the freeze plug behind the engine mount so neither car nor engine on stand are running yet. :rolleyes:
     
  15. knucklebusted

    knucklebusted Well-Known Member

    No spare 350s or even any 350 parts. This is all starting from scratch. I have the Stage 1 car so down time is not really a concern on the 350 car.

    BTW, that's how I did the Stage 1 car back a few years ago when I put the Edelbrock head motor in it. Accumulated enough parts to build a spare motor.
     
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  16. patwhac

    patwhac Well-Known Member

    Ah I see! Well if downtime is not a factor and you have the budget go for it!

    I will start an official build thread for my car/engine one of these days. Still in the planning process but getting close to ordering my camshaft. Scott Brown from buyracingparts.com will grind you a custom cam for the same as an off the shelf cam (~$200) so if you decide to get a cam it might be worth it to give him a call. He just quoted me for a turbo grind.

    I wish you were close to me because I have an extra 350 that I need to get rid of, thought I was going to use it for my build until I found the one with good compression. I may dismantle it and try and sell the parts, so if you want/need anything let me know! I would probably give it away as a whole if someone came and grabbed it . . . just need the space back!
     
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  17. knucklebusted

    knucklebusted Well-Known Member

    I might call Scott Brown when I get to the point of pulling the trigger. For now, there is no rush if it won't come apart easily.
     
  18. hugger

    hugger Well-Known Member

    You will call,...and call,...and call but don't get your hopes up
     
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  19. Mart

    Mart Gold level member

    Scott answers emails quicker than his phone.
     
    alec296 likes this.
  20. patwhac

    patwhac Well-Known Member

    Yeah I never tried calling him, but he emailed me back the next day!
     

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