350 rebuild help

Discussion in 'Small Block Tech' started by 350GST, Oct 1, 2002.

  1. 350GST

    350GST never done

    Hey guys! I just joined today and I had few questions. I have an 84 T Type that has a 72 GS 350 in it that I bought about a year ago. The motor is pretty much shot and I'm planning a rebuild in the next month or so. This is my first project and I need a little help with some parts matching.
    So anyway, what I'm trying to achieve is around mid 13's in the quarter on pump gas (93 here), with a decent idle. Is this possible? A little more info: the car has 3.42 gears, a 350 trans, and I will be buying a 2500 rpm stall converter. I'm not sure of the cars weight, but I believe G bodies weigh less than a bodies.
    Here are a few more specific questions:

    1. The oiling seems to be a problem on these motors. In what ways can it be improved internally and externally?

    2. The rear main seal needs replaced often. Will purchasing a neoprene one solve this problem or is another factor causing it?

    3. What would be a good cam choice for pump gas compression? I already have headers, dual exhaust, and a Poston S Divider intake, so breathing isn't a problem.

    4. Holley 750 vac. sec. or Q-jet? I'm going for best milage possible.

    5. Who makes a high performance fuel pump for a 350? Or should I buy a Carter electric pump?

    Sorry, so many questions to bug you about. Nobody 'round here knows a thing about Buick stuff. Any help would be greatly appreciated. Thanxx!!!
     
  2. dariggs

    dariggs Well-Known Member

    ENGINE BUILD UP

    POSTON ENTERPRISES CAN HELP YOU OUT. 1-800-635-9781. THEY HAVE A CATOLOG WITH ALL PARTS NEEDED FOR YOUR REBUILD. THEY ARE VERY HELPFUL.
     
  3. custom sky

    custom sky Generally Nice Guy

    Welcome to the board:)
    I'm sorry I can't use your name. You should go back to your user settings and put your name there so we know who you are.
    Now to business.
    I am in the process of rebuilding my 72 350 right now. I'm taking every opportunity to document my build up so I can help others that don't know what to do on a 350 build up. I can't tell you what to do with your engine but this is what I am doing with mine. First I did a lot of research to find the best price on the best parts. I have a budget that I can't go over so for me I didn't go with all the most expensive parts I could find but I didn't skimp on the parts that I chose.
    List of parts:
    I went to ta performance for just about every thing I needed.
    I chose forged pistons to give me longevity in my engine. this is my daily driver and I want it to last for years. I also like to step on the gas (all the time).:laugh: I chose to use chrome molly rings. They may or may not last as long as the total seal plasma rings but I don't plan to use nitros or any other pwr adder and the plasma rings would be over kill. If you want to use a pwr adder you may want to spend the extra $100 for the plasma rings. You can't even consider an engine build with out getting TA performance heavy duty cam bearings. Your engine will thank you. I didn't have the money to upgrade my rods to 73 and later which I have been told are stronger than the 72 and earlier rods. The 72 rods are porne to rod bolts breaking . TA has new bolts made by ARP that you can't get from ARP if you can believe that. I highly recommend using the new bolt. Make sure you check the diamiter of all the rod bolts to make sure all the bolts are the same size and that you can get the right replacements. I had one bolt in one rod that was bigger then the rest and had to replace the rod sence no one makes the bigger bolt yet. My machinest told me he thinks the 72 rods with the new bolts are better than the 73 and up rods. He thinks the 72 rods are easier to work with.
    The best way to go is to get a complete kit for your engine. I upgraded just about everything in my kit. Buy a oil pump booster plate. It will help your oil pressure without wearing out your cam and bearings from excess front engine load. Now some people say the 350 has the same oiling problems as the 455. I personally have never encontered such problems so I don't know that much else needs to be done. Other people on this board may have more information that could be helpful.
    Machine work is every thing. I called and talked to 10 different machine shops before I choose one. I paid to have the short block balanced which will increase engine life. Well worth $200. I chose to up the compression from 8.5/1 to 9.8/1. I live at 5000 ft. elevation and I really need the extra compression. This will allow me to use my TA 212 cam that I bought and used when I was in California(it just wouldn't work at higher elevation with such low compression). Have the crank oil holes chamfered it they aren't already so you don't have to worry about scoring your new bearings when you put it back together.
    I was getting 15 mpg around town with my Q-jet. I have a 2500 stall converter with the origional turbo 350 trans. 2.5 inch dual exhast and 273 open rear gears. I expect to beat this performance with my new engine. I hope that I have been some help to you. In the near future I hope to have my pictures on a web site to let every one take a look.
    Good luck and let me know if I can help you with any thing.
     
  4. 71ConvtSkylark

    71ConvtSkylark Well-Known Member

    Welcome!

    First thing, it seems like there arent as many small block people on this board, so well help as much as we can.

    Oil, as mentioned, the thrust plate for a nice end surface, and also buy the gasket shim kit from T/A. It is amazing what this will do for your pressure. Get the end clearance to your pump to .002. This will give you good idle oil press.

    I used hyperutectic flat tops on my motor, and love them. However, make sure your shop knows your using these pistons, as they require a tighter fit than stock cast, as these pistons dont expant like the cast do. You dont want a whole lot of side room in the cylinder wall. If the shop says its just like a cast piston, walk away.

    If you want driveability, and speed, I recommend a 200 4R trans instead of your TH350. This will give you a 4 speed instead of a 3, and allow you to run a 4.11 gear and still have a decent highway/cruising speed. The 200 4R has an overdrive of .67:1, so you do the math. I am doing it to my Skylark. I have an RPM cam in my motor that I had Schneider Racing Cams custom grind me(488/502 lift, 230/238 Dur@ .50 on 110 degrees. The cam cost me $120, and it was worth it. The rest is just flow work on the heads. But what I mentioned above will give you good results at a fairly cheap price.

    Neoprene Neoprene Neoprene Neoprene Neoprene Dont skimp on this rear seal!

    I use a holley 750 and it really woke my motor up from the q-jet. Its all prefference.

    Hope this helsp some.

    -Jon
     

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