383 Stock Rebuild Parts?

[SlinktRR]

Do the 438ci stroker, there is a good article on a 438 build (Google search) that you could duplicate. if you don't have the rods you might as well get a kit for a more rev happy 438-451 type.

 

[fj5gtx]

please do tell ive only done a few rebuilds so always learning

[low compression parts] So what happens is sometimes the replacement pistons are a little shorter and don't come to the top of the block, resulting in more space between the head/valves and the top of the piston when its at tdc. That accounts for the denominator in the compression equation... when you divide by a larger number, the result is smaller.... thus less compression.

You can try to compensate for that problem by decking the block, shaving the heads, and using a thin head gasket.... but its less expensive to get the right pistons. Unless you need to deck and shave to correct the old iron.

I think if budget is limited, it is better to spend on the heads/intake/cam rather than increasing displacement. Unless you don't like huge chunks of aluminum under your hood.

Another thought if budget is limited. Measure your 383 bores, see if you can use standard pistons. Then find a couple set of good used ones from a pre-71 block. You could research the compression ratio the factory rated them as, and get pistons from that vintage. You might even find someone with good used rods, but be careful as sometimes magnafluxing and resizing can cost as much as new ones.

 

[1KoolBee]

One thing about the 383, you’ll hit valve float long before the stock rod with good bolts comes apart. I proved that one out many times as a teenager When I did my Bee’s #s matching engine, I used forged trw’s and I took a couple of sets of stock rods and inspected them carefully. I found that one of the originals was actually bent slightly and another had the bolt head seat improperly machined, the rod bolt was sinking into the seat, and seat was starting to crack. Would have blown eventually for sure. I measured all the rod lengths and weights and came up with a set that was pretty close. Had them magged, resized, shot peened and balanced, installed ARP bolts. Here’s where I would have done things a little different. Upon reassembly I should have mocked it up and I would have seen that the trw’s were down in the hole about .020. I should have had the crank offset ground .015-.020 to bring the piston up to near zero deck and increase compression plus get some quench. As far as the stroker goes, I’m working on a date correct 383 that’s stroked to 451 with stealth heads. I had a Dwayne Porter custom solid cam ground to work with stock manifolds. Looks bone stock. I figure if I blow it up, I lose a lot of money but not my original motor.

For pistons on a stock build, I’d consider these:

ICON BBM Dome Piston Set 4.290 Bore +4.5cc IC687.040 800745243928 | eBay


451 rod/piston, you could probably do a stock rebuild for near what a set of these cost.

 

[SlinktRR]

1koolbee, what compression height and length rods you using in the 383 stroker?

 

[1KoolBee]

The CH is 1.320 Diamond flat top pistons (51950) with a 6.700 BBC rod designed for a ford stroker (centered pin axis, chevy is actually offset) and a 3.91 stroke 440 source crank. You could do this with an offset ground 440 crank turned down to BBC rod journals. Compression is approaching 11:1.