287 In the Rambler, or 327?

I've been told that some of the early blocks (came out in late 63) have thick cast cylinder walls, basically the same cores as the 327 except for the bore. Sonic checking is certainly a good idea! But boring out 0.250"???? That's a LOT, and I seriously doubt the cylinder walls are 0.375" thick (which would leave a 1/8" thick wall after boring). Then core shift has to be considered. I know the old engines will take a 0.125" overbore, but getting pistons might be a problem. Jeep 4.0L six bore is 3.875" though, so they might work -- would have to check pin height. That would make a 307 (306.62).

 

4-barrel intakes from marine fireball v-8's have canted carb mounts to compensate for the angle of the driveshaft exiting the bottom of the boat. You could probably find a canted adapter plate used with boats that had automotive intakes and mount it backwards. I had a couple of old wooden boats with amc engines in a past life! The dual sidedraft intakes had o-ring seals on the carbs that were always leaking and were a pain in the ass! The dual side drafts were an attempt to get the engine height lower to fit in tighter engine compartments. The 327's were smooth, good running engines though.

 

Farna--think about what you said. Boring out the 287 is only .125" removed from the wall, not .250". That is the total increase in the Diameter. IF the wall was .325 and .125 was removed, the remaining wall thickness would be .200". This is more than what is left on a SBC when it is bored. Opinions and thoughts are great but backing them up with actually doing it makes a little bigger leg to stand on. Dont mean to get in a pizz'n match with you but think about your math! Sometimes I need to stop and think too before I post.

 

Smaller engine but a powerhouse anyway is the '66 and later 290. Dad had one that we drag raced and did very well with. We lost the tailshaft housing on that one (didn't tighten the U joint bolts enough after changing out the 4.11 posi we used when racing) hauling down the highway. Dad replaced the 290 with a '69 343 and shift command auto instead of just another tranny. I wrecked (bad boy, bad) that car. A friend gave dad a '65 American and we put the '69 343 and trans in that. By using the front, V8, crossmember from the '66 it was a bolt in swap. The '66 also gave up it's rear end and radiator.

 

Duh! Yes, you're correct Rebel 327! Only taking 0.125 out of the wall. Still, that's a lot for most engines. I've been around AMCs since 1979 and few have tried to punch out a 287 to 4". I only recall one person who did it, and they had constant overheating issues. I think it was a later model block though, 65 or 66. Everything about boring that block is speculation. No one has actually taken a block (early or late) and had it sonic checked. That would be the first thing to do before boring even 0.125". I'm confident the old style casting will take a 0.125" bore, but I only know of reliable engines bored 0.060" for sure.

 

Farna--when you say "No one has actually taken a block (early or late) and had it sonic checked."--how do you know that??? I have done it and maybe I am the only one but I doubt it, not sure. I don't post all my results since there are too many people that want to be experts on this engine and only work on recollection and conjecture. Most just guess. I just do it and try and help people where I can. You have done a great job of informing people but you jump to lots of conclusions when you say few, no one and most. Maybe you are hooked up with everyone that is working on these engines as I am not. Boring the 287 more than .060" to less than 4" bore will create havoc in finding pistons due to the compression height of the pistons and the very tall deck height of the block. Obviously easier just to keep overbore on a 287 to .060" and less or move on to a 327. We both want to help people but we just have different ways to do it I guess. If anyone wants to see it, my 327 engine with modified toquer intake is pictured on the intakes thread on the AMC Forum. My engine with headers is also pictured somewhere as well. Just FYI.
Keep the Gen I's alive--rebuild em and run em.

 

You're correct -- "no one that I know of" is the way I should have worded that. Since you've had one sonic checked I'd certainly like to file that information! It would also be nice to know the year of the block and/or the casting number. I've only got one casting number listed, but that doesn't mean there wasn't another one or two.

I agree with you, there is too much conjecture and not enough fact (and I gather the facts whenever I have them). Most of the people I know who are messing with GEN-1 AMC V-8s are using the 327 block, most just rebuild the 287 or swap it for a 327 or newer AMC V-8 -- or a Chevy (occasionally Ford or Chrysler). I'm certainly not hooked up with everyone working on these things, but am with several people. I tell those who ask what I know, and am usually careful to tell them what is fact and what they just have to check for themselves. Sometimes I slip up by thinking/typing too fast!

 

Idea came to me.

Pontiac rods.

Oldsmobile 4.125 inch pistons.

Anyone know the pin height?