302 conversion on a 70

Discussion in 'Technical' started by satchelmcqueen, Feb 12, 2019 at 3:43 PM.

  1. satchelmcqueen

    satchelmcqueen Member

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    so ive decided to let my stocks ride for a few more years in the market and will not be putting in a 347 until at least 3-5 more years.

    i have decided to use the 302 i have in my garage instead to hold me over and get that mean v8 sound back, so i have a few questions if anyone can help and knows for sure the answer.

    this will go in my 70 maverick that has a stock 200 as of now.

    so the 302 is a crate motor (jasper engines) that has around 80k miles on it and its always been a solid reliable engine. it was a rebuild of course from the vendor. i ordered it to replace the old 302 in my 70 f100. it seems to have a slightly bigger cam in it but im just judging from the sound vs the stock sound.

    with that said this is a 70f100 302 replacement engine and will be mated to a 72 maverick 250cid trans im getting from my donor car.

    what parts will i need to hook up the trans? can i use the 250 TC or will i need a newer one for a 302? also do i need a 157 tooth flywheel? what weight? the harmonic balancer on the 302 was the same one that was on the 70 f100 although i will use a new one this time around. im assuming its a 28oz. correct me if im wrong please.
    also, can i use the 72 maverick trans cross member for the install to my 70 mav? im not to worried with the v8 dual exhaust notches because ill be doing about a 4' pipe extension off each header and run it straight to come out in FRONT of the back wheel.

    i already have the 302 engine mounts and perches so im good on that at least. i hope to start on this in a few weeks as itll be cheap compared to what i was going to do.

    please advice on the following....

    ....can i reuse the 250 TC? also what stall should i shoot for with a mild 302 if i need a new one?
    ....what flywheel do i need for the 302?
    ....what harmonic balancer do i need to match with flywheel?
    ....is the 250 trans mount ok on my 70?
    ....can i use a new 70 f100 302 starter or do i need a 72 maverick 250 starter?
    ....the rest i think i have it covered.

    thanks all
     
  2. Krazy Comet

    Krazy Comet Tom

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    The 250 transmission hookup should be mostly, if not same as 302. Linkage bolts to back of edge of block that is same as 302.
    Torque converter will work but you do need a 157T, 28oz flexplate, 250 is zero balanced. I have a 2200 Hughes in my Comet.
    Any pre 1980, std 302, harmonic balancer should be fine.
    Starter should be fine, though I'd convert to a late PMGR from a 5.0 Mustang, F150 etc. 1992-1995. I have a $35 ebay special on both my Comet & beater F-150.

    I understand the later crossmember will require some mod to fit in '70 model. No direct experience.
     
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  3. satchelmcqueen

    satchelmcqueen Member

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    Got it. But to clarify do you mean the 250 starter will work or the 70f100 starter?
     
  4. Krazy Comet

    Krazy Comet Tom

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    The starter for 250 should be exactly same as the 302 starter. It bolts to bell housing, not block.
     
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  5. groberts101

    groberts101 Member Supporting Member

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    For ease of install(more ground clearance too) and to avoid the commonly available "too big" primary and secondary(collector) sizing of 1-5/8" x 3".. I'd research the many threads around here in regards to hedmans 88400 shorty versions.

    They are much better suited to a smaller CID stock'ish/slightly warmed motors with their 1-1/2" x 2-1/2" primary/secondary sizing. Slightly more responsive and can hit the stock converter harder when flashed from a standstill. It's nothing huge but every little bit of extra torque helps these little motors get the car moving.
     
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