366/427 tall deck engines

[cv67]

I hear these are small bore/small valve workhorses havent seen on e in ages

What would keep someone from making use of one in say a 3/4 ton truck with a tall gear?
Suggestions? Id guess basic bowl work, small cam, headers would get it done for not much ?

ANy more info about these?
How far can they be bored?

[tt 383]

I hear these are small bore/small valve workhorses havent seen on e in ages

What would keep someone from making use of one in say a 3/4 ton truck with a tall gear?
Suggestions? Id guess basic bowl work, small cam, headers would get it done for not much ?

ANy more info about these?
How far can they be bored?

My understanding is the 366 was thin wall casting and will get you .125 over for 4.060 max bore from 3.9x standard bore. 1 Guy on Team Chevelle said some won’t even take .090 over... Kind of wonder the point of that engine?

[BillK]

The 427 is 4.250 bore. I would think that you would be safe up to .060" overbore in that application. Need a tall deck intake manifold or spacers if they still make them. Not sure if i would mess with the 366. Not sure if I would mess with it either way unless you have one ready to go. 454's are still fairly easy to find and would be a much easier fit.

[ProPower engines]

They used to be popular some years back by using the 427/454 block in conjunction with 496 stroker kit and a
6.800 rod in super charged applications but other then that I think the rod would be too long for a N/A build.
The intake is more as we all know its much wider and the spacer deal seems to never go well for a DYI from
what I have seen if a shop that does good head work is involved the results will be better in most cases.

The 366 is GM's 351M. Low basic output just to move the truck. If the compression is up and a bit of head work is
done they make a good engine for a PU. I say this because I did have a 366 in my shop truck for a few years when
I was between the 540 and now 620 builds just as a driver it was fine but not a power house.

They seem to be used in older gas fueled model 5 ton stuff meant to be used in town off highway in stuff with real low gear
like milk delivery trucks which is what I had got a core from.

[cv67]

Thanks.
So the 427 had a bigger bore?
What kind of stroke could be stuffed in there? I assume these were all 4 bolt blocks?

Would the rod be too long if one didnt use a coffee can size piston? Enjoy builds that are different even if they arent a big # deal.

[ProPower engines]

Thanks.
So the 427 had a bigger bore?
What kind of stroke could be stuffed in there? I assume these were all 4 bolt blocks?

Would the rod be too long if one didnt use a coffee can size piston? Enjoy builds that are different even if they arent a big # deal.

Depends on the year. They are a more costly build with the funny pistons and ring set up

[Little Mouse]

The 427 tall deck truck and marine block most people are able to bore them .100. Simple case of going to a .400 longer rod and using pistons for the passenger 9.8 deck blocks, all kinds of manifolds for them now as long as it's a single plane. 6.535 rods are as common as dirt on the ground today.

[racear2865]

The 427 will go over.125 but sonic check for centrality. It will take 4.375 stroke id you use stroker steel rods. No aluminum. Watch when you cut the oil gallery side as it will go thru in a heart break. Going that large on bore will only help you on the intake side of the head. Check the head hangover at the intake and if you got some, chamfer the intake spot.
reed

[tt 383]

Eagle did have rotators for 4.500 stroke and 30/60/100 overbores.

[racear2865]

Eagle did have rotators for 4.500 stroke and 30/60/100 overbores.

Good luck my friend if you try a 4.5 stroke When u hit oil give me a call so I can make money on the oil.
reed

[tt 383]

Eagle did have rotators for 4.500 stroke and 30/60/100 overbores.

Good luck my friend if you try a 4.5 stroke When u hit oil give me a call so I can make money on the oil.
reed

I never said it was smart, but it has been done by a few brave men. The 4.375 x 4.310 seems like a good fit IMO.

[Schurkey]

Thousands of years ago, GM built some 482s for boat racing.

"Tall-deck" 427 truck block. Ordinary compression height 454 pistons. 4.25 stroke crank. The "special sauce" was the 6.405" connecting rods.

Today, I suppose a person would use short pistons and a longer rod.

SOME 427 truck blocks are cast with clearance for the 4.25 stroke crank. Others aren't.

[Alaskaracer]

Honestly, with the availability of aftermarket blocks, I don't know why anybody would even consider using one of those for anything other than a replacement engine. With the oil gallery in the pan rail, you're stroke limited, and many didn't have the thickest cylinder walls to begin with. IMHO, the 366 is a waste of money, and the 427 offers no advantages of any kind over a decent aftermarket block. By the time you get all the proper machine work done, you're already at the cost of a new block anyway....and one that is designed to handle the hp of todays modern high performance engines...I get it, back in the day they gave you options. We didn't have the stuff we do today. But that's a moot point now, and unless you're just dead set on using one, I see no reason to put on into any performance application. Much better choices out there for about the same money.....