392 or 416 that is the question?

[MoparDart73]

I recently bought a 340 block stand bore. Hone not bored. The cylinders wall look great at 4.042. Now is there any way to find out what car the original block came from by using the partial vin # 127282. And next question is should I just stroke it has it is to make a 392. Or just have it bored to 30 over to make a 416. As I can tell they both will create about 425 to 475 hp pretty easily. Thoughts?

 

[33 IMP]

If you give us the two digits ahead of the six you gave, we can tell what year the block is, and what assembly plant built the car it was in, but that's about it. Example: 9Bxxxxxx would mean a 69 assembly, from Hamtramk.

 

[33 IMP]

Your 340 block with a standard bore and a 3.79 stroker crank would be 389, cu in, 394 with a .030 overbore.
Standard bore 340 with a 4" crank is 410, .030 over is a 416.
A 392 is usually a overbored 318, with a 4" crank.
I'm guessing there are very few standard bore stroker pistons available,.... if there are any at all!

And welcome. I'm just across the river.

 

[DeltaV]

I recently bought a 340 block stand bore. Hone not bored. The cylinders wall look great at 4.042. Now is there any way to find out what car the original block came from by using the partial vin # 127282. And next question is should I just stroke it has it is to make a 392. Or just have it bored to 30 over to make a 416. As I can tell they both will create about 425 to 475 hp pretty easily. Thoughts?

View attachment 1947205

View attachment 1947206

I have nothing to offer to answer your question, but I'm curious which heads/valves you plan on using.

 

[autoxcuda]

To get 425 - 475 HP out of a 416” with 4” stroke crank, common combo will be more head flow with

edelbrock aluminum heads (425 HP)
Trickflow ported heads, or ported edelbrock heads I’ll (475 HP)
1 3/4” TTI or Dougs headers
240 -250 deg @0.050 cam (250+ for 475hp)
110 centerline
RPM intake (425 HP)
M1/trick flow/victor -intake (475Hp)
9.5-9.7:1 compression
750 holly-type carb

Will make street friendly HP.

I’ve run a 416” in my Barracuda since 2011 with setup in this range.

 

[MoparDart73]

I have nothing to offer to answer your question, but I'm curious which heads/valves you plan on using.

I wanted it to look pretty much stock. So I had a machines get me two 73 heads and put 2.02 intakes and 1.6 exhaust valves to make like the x heads made the chambers 68cc

 

[Krooser]

I am not a fan of those long stroke small blocks. They are ok if you have a trailer queen or just wanna impress the tuner crowd at the Dairy Queen cruise night.

But for a car that will be driven a lot those long strokes wear out the cylinders way too fast for my tastes.

My son used to be a caretaker for a 30 car collection of mostly muscle cars. One was a '68 Dart with a long stroke deal. I wasn't impressed.

My last dirt track small block was a 4.060 360 block with a 3.79 stroke deal. Had dyno'd at 650 horse on a skimpy dyno. I rebuilt it with a better cam from Jones Cam Technologies and lighweight 13-1 slugs and we figgered we were bumping up against the 700 mark. And it was happy at 6500 rpm.

But HP aint everything.

Put some good flowing heads on it and run a big bore/ shorter stroke deal. You will get all the power you need with a longer lasting more streetable combo.

And make sure the cam you choose was ground on a Mopar 904 friendly core. Big difference in power.

Just my opinion.

 

[MoparDart73]

This stroker kit says i will have around . Is it not correct.

If you give us the two digits ahead of the six you gave, we can tell what year the block is, and what assembly plant built the car it was in, but that's about it. Example: 9Bxxxxxx would mean a 69 assembly, from Hamtramk.

They are 3b. I know it a 73 block date 6.1. 72 and it is hamtramk. But when I referenced it there. It has not been reported.

 

[autoxcuda]

I wanted it to look pretty much stock. So I had a machines get me two 73 heads and put 2.02 intakes and 1.6 exhaust valves to make like the x heads made the chambers 68ccView attachment 1947245

Are the heads ported?

Are you going to run headers?

Do you know how much they shaved off the heads to get to 68cc ? That’s the low end of the “advertised” cc rating. Most are around 72 cc when actually measured.

They gave you a doc with the measured the cc’s for each head?

 

[autoxcuda]

The rod ratios on a small block mopar with 4” stoke are very close to many production V-8 that for years have successfully been run to high mileage.

 

[Runcharger]

I believe that thicker cylinder walls are of benefit. I have an engine bored the least amount possible.