I want to convert my 73' 455 to a infamous 70' stage 1

Discussion in 'Street/strip 400/430/455' started by Always Cool, Apr 15, 2018.

  1. KenneBelle455

    KenneBelle455 Well-Known Member

    No doubt, I just shake my head when I see people kneejerk to the loudest, least effective changes like larger/louder exhaust, that will do absolutely nothing to improve the power of a smog-choked '73 455. Steeper gears will help some with off the line acceleration, but isn't going to gain him much of anything when he punches it from a roll. These are kneejerk, inneffective modifications that do little or nothing to serve the end goal of more power, but they make the car less enjoyable to drive and potentially less reliable, so what I advocate for is a real plan of attack instead of just throwing on some easy stuff.

    When I put my Pontiac together, I had a solid plan and put together a good solid torquey motor that makes fairly impressive power/torque, yet still has a smooth idle and good daily drivability, and it runs through stock style 2.25" duals with stock style mufflers. Smooth idle and quiet exhaust, but loads of lowend torque, good top end and very fun to drive, with 3.08s out back and tall tires that allow it to live comfortably on the freeway. Mid-3 gear ratios, big exhaust with stock manifolds and a smogged out 455 is a very poor combo, frankly. Totally ineffective.
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  2. Always Cool

    Always Cool Active Member

    I appreciate the response and advise. I'm wondering what type of oil and filter do you suggest? And does anyone no the approximate cost of those TA parts are?
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Wix 51258 Filter. https://www.fleetfilter.com/filter/51258.html

    As far as oil is concerned, it is important to use an oil that is engineered for flat tappet engines. An anti wear additive called ZDDP is being engineered out of motor oils for modern engines, mostly for emissions reasons, and because new engines have roller valve trains. Read more here,

    Some use an additive called ZDDP plus that you can add to any motor oil you buy.


    I prefer to buy oil that has the proper balance of ZDDP and detergents. It is more expensive though,


    Before you think about replacing your timing cover and oil pump, install an oil pressure gauge and see where you are. I bet your oil pressure is fine.



    The TA Performance timing cover is a great product. It's expensive though, another reason not to replace something unless it is broken.

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  4. Always Cool

    Always Cool Active Member

    I agree. When you say highway speed, do you mean anything above 80 - 90 mhp? I keep this car down in Oklahoma where the turnpike speed limit is 75 so every now and then I stretch her legs out when I get a chance. She sees less than 700-900 miles a year if that. Usually I keep her between 45 to 70 mph. I'm a young man with an old soul.
  5. Always Cool

    Always Cool Active Member

    I should've mentioned earlier that I bypassed the smog pump years ago. I don't know if that matters or not? I have the A/C bypassed as well but I plan on reconnecting the A/C in the future though.
  6. Always Cool

    Always Cool Active Member

    Thanks for the heads up. I'm nervous about the rumors that I've heard about the oil pressure issues with these engines. So I think I'm going to have to look into the price of that TA setup. Like I said, preventative maintenance is my main goal.
  7. KenneBelle455

    KenneBelle455 Well-Known Member

    Why? Just install a good oil pressure gauge and see where it's at. Odds are it's just fine, and if it's fine now it will very likely stay that way with good care and oil maintenance. No need to jump the gun. The oil on my classic cars gets changed at least every six months no matter how fuel miles I put on. Condensation, fuel and other normal byproducts of combustion build up in the oil and contaminate it, and that stuff is still in there breaking down your oil even when the car sits. Also, if you know you're going to park it for an extended period of time(ie months or more) always change the oil right before you park it.

    Follow these simple rules and you're not going to suddenly have oil pressure issues develop if you don't have them now. If you're worried about proper/preventative maintenance, follow these basic steps and you'll be fine. Spending more than a grand to replace your timing cover/pump gears is pointless if you have nothing wrong now. I say over a grand factoring in gaskets, fluids and possibly labor, though it sounds like you may do the work yourself. I think a loaded cover from TA is around $750 or so. A great investment IF you are actually in need of a new cover/pump, but a waste of money if what you have now is working just fine. Something as cheap as a $20 mechanical gauge is all you need to verify your oil pressure, so that should be your first step.
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  8. Always Cool

    Always Cool Active Member

    I'm glad to hear your thoughts and am wondering where I would plum the sensor and wiring for a mechanical oil pressure gauge at on those pumps?
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Sometimes I assume that everyone is computer savvy enough to recognize a link, but I linked you to this thread on gauges,


    Click on the above and read it.
    Always Cool likes this.
  10. Always Cool

    Always Cool Active Member

    Thanks a lot. I'm assuming that my father and I should be able to figure out how to install the sensor and gauge.
  11. buick64203

    buick64203 Right wing conservative Staff Member

    You would be surprised how much power you can get by doing some basic things. For example, that 73 455 could benefit greatly from reading Larry's power timing thread. Put some extra initial advance in it, re-curve the distributor and get the mechanical in faster. It literally felt like I installed another engine in my 72 GS after that.

    You can adjust the tension on the secondary air flaps. I also take a pin drill and open up the restrictor a little on the primary choke pull off so it "unloads" faster.

    Check to make sure that the accelerator cable is opening up the carburetor fully when you mat the gas pedal. Little things like this make a huge difference.
    Last edited: Apr 16, 2018
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  12. Always Cool

    Always Cool Active Member

    Thanks for the info. I'm glad to see that minor routine maintenance can such an improvement. Even though I've owned this car for 18 years, all I've done is drive it and replace the head gasket other than fluid changes and brakes. I just fell in love with the body style at first sight. Believe it or not, I bought that car for $2,000 about 18 years ago.
    Last edited: Apr 17, 2018
  13. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    With your backround I would consider putting a torque monster diesel motor in it.
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  14. Always Cool

    Always Cool Active Member

    If I had no idea about the history and heritage of Gladys that might be entertainingly possible. But unfortunately, I know what side of the bread that my butter is on with this car.
  15. tommieboy

    tommieboy Well-Known Member

    "But I'm at 52,637 miles now....."

    You're getting up there in miles for the heavy car like the 73 Riv. Bone stock, that engine may have a lot of life left in it, but not so much so when it comes to modify it for more HP / torque.

    At the minimum I'd have a mechanic (that you trust) check the following before you consider upgrading the engine vs rebuilding.

    1. Run a compression test on all of your cylinders.
    2. Check the condition of your ignition system, including all of the wires / cables.
    3. Check oil pressure at idle and at your max RPM (your current setup might max out in the mid 4 thousand range)
    4. Check oil flow at the rockers, and check for wear on the shafts and rockers wear surfaces. Good oil pressure in the front of the engine does not always equate to good oil pressure / flow at the back of the engine.
    5. Confirm what your current differential gear ratio is. If it's a posi, make sure it actually works.

    The following involves some engine disassembly / reassembly, so it's not always feasible for every DIY's as sometimes thing don't want to go back in the right way once they have been disassembled; especially on higher mileage engines.

    6. Check the condition of the nylon teeth on the timing chain as a lot of it ends up in the oil pan on these older engines. This is a good time to inspect the timing chain cover / oil pump assembly too.

    I'm sure I missed a bunch on the list above but it is a good start.

    On my 71 and 72 Riv, I got the most bang for the buck / fun with the following setup on the street (no strip, limited highway use):

    Factory Stock cast iron intake / Quadrajet
    KB Mark 1H camshaft
    KB Oil Pump Booster Plate
    Electronic Ignition (nothing fancy)
    Ported small valve cylinder heads (rebuilt with KB springs, stamped steel rocker arms)
    Factory Stock Exhaust Manifolds
    Factory Stock Dual Exhaust plumbing (mufflers and resonators), I liked the sound of the factory dual sound so much on the Rivs, I just left it alone.
    3.42 Posi (took forever and a day to find one these, even in the mid 70's; I eventually found two complete axle assemblies and just did a complete swap-out on both cars). I needed to get a transmission guy to adjust the shift points on the TH400 to make better use of the KB Mark 1H camshaft and the 3.42 Posi. My original gears were 2.93 non-posi. Truthfully the 2.93 non-posi had its own set of positive attributes over the posi unit on the street and highway.

    My friend had a very similar setup in his Riv, but used the KB Mark 2H which was a step up from the KB Mark 1H. I preferred the street mannerism of the KB Mark 1H over that of the KB Mark 2H, so I just stuck with the KB Mark 1H. He much preferred the KB Mark 2H.

    Oddly enough in cleaning out the garage this past month, I just stumbled upon my old Edlebrock B4B / 9800 Thermoquad combo that I used briefly on the 71 Riv. I took it off so that my friend could try it out on his Riv, but he never got around to installing it, nor did I feel the need to reinstall it on my Riv. Still it was a nice surprise to see it once again. It was in a box marked "KITCHEN". duh! And my old KB polished aluminum valve covers were in a box marked "BEDROOM 1". duh, again! It brought back a lot of fond memories.

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  16. Always Cool

    Always Cool Active Member

    I'm kinda leaning towards going through the block, inspection wise, and replacing what's needed with stock parts along with the TA timing cover.
  17. Julian

    Julian Well-Known Member

    Are those valves right? I know the diameter isn't. Going from 3/8 to 5/16 ..if there are any would add weight and hurt flow. Typically go thinner to 11/32. I didn't think you could over 2.16/1.75
  18. johnriv67

    johnriv67 Well-Known Member

    I can neither verify his engine nor confirm the sizes, but I am only repeating what I was told, which may be a problem in of itself. Also, 5/16s is thinner than 3/8s AND 11/32s.
    Last edited: Apr 17, 2018

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