New motor in a 78 monte

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Mike Geepers

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Feb 1, 2018
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My concern would be the toothpick 26 spline axles trying to twist those tall tires.
Mine is too, though ive seen and rode big tires on the g bodies. I have seen some threads where they have swapped A body rear ends for the 12 bolt, and Ford 8.8 rears from certain year mustangs with conversion kits and slight modification. Will def check into that when car is apart. But yea you right
 

pagrunt

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If you're going for a 12 bolt look into '64-'67 cars as those are the narrowest of the earlier A's but still about 2" wider & will still need a adapter control arms kit.
 

jiho

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jiho

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smog inspection sans the inspection

?!? Know of no such thing in California .... *legal* that is.

And if you do find a place, when they get busted you're stuck.
 
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scoti

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Sep 5, 2019
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You've stated 20" wheels but what size tires? OD of the tires plays into the math on a good combo.

3.08's, a TH350, & a 27" tall tire will not roll down the highway @ an OD-trans RPM range (around 2700rpm vs. 1900rpm @ 70mph). But, around town, the 20"/27" OD tall tire combo, those 3.08's & a 2.52 1st gear is going to make the car possibly feel like a slug w/o torque. To change that, you need to consider everything when selecting parts for a budget approach.

A good example was your statement of possibly using an OD trans. A 700r4 has a steeper 1st gear @ 3.06 which helps the 3.08 gearing/27" tall tire combo take off better. But, you now have to factor in the cost of the trans swap. Changing rear end gears helps w/your current TH350 trans but might make highway drives not as pleasant. Cam choice needs to be along the lines of something that helps torque production & works w/the rest of the combo. Too big of a cam, and/or heads & intake that aren't matched to the cam, & it can be a dog.
 
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Mike Geepers

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i have 235 35 20 tires on it and all i know is they are heavy as hell. Which is why i figured the drivetrain is underpowered to push it. I just want good acceleration on takeoff and cruise on the highway once in awhile, but mostly cruise around town. My choices are a rebuilt motor from summit that comes with a warranty and just will need accesories, an A body monte 350 that was given to me and i can put what i want in it, or rebuild my 305. I may keep the th350 and just change the gear oil. All this math makes my head hurt but I am keeping at it to find the right combo. 565bbc shared a link that had a nice 355 c.i. with 64cc heads. I like that but this build will be old skool no LS motor no efi just simple for me to work with. Thank you forum for all the input, anymore questions i will ask or feel free to ask
 
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scoti

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i have 235 35 20 tires on it and all i know is they are heavy as hell. Which is why i figured the drivetrain is underpowered to push it. I just want good acceleration on takeoff and cruise on the highway once in awhile, but mostly cruise around town. My choices are a rebuilt motor from summit that comes with a warranty and just will need accesories, an A body monte 350 that was given to me and i can put what i want in it, or rebuild my 305. I may keep the th350 and just change the gear oil. All this math makes my head hurt but I am keeping at it to find the right combo. 565bbc shared a link that had a nice 355 c.i. with 64cc heads. I like that but this build will be old skool no LS motor no efi just simple for me to work with. Thank you forum for all the input, anymore questions i will ask or feel free to ask

That's 26.5" tall. Super short sidewall won't offer much resistance to spinning so a mild 350 combo like he posted would work for you.
 
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