Originally Posted by augiedoggy

Ah yes your right I was thinking bore size only not stroke which makes more sense.... I would also need to replace my 64cc heads if I wanted a street friendly pump gas setup right?

Originally Posted by gkull

64 cc are better. You just buy pistons with more cc of dish. Or up the cam lobe duration to get the Dynamic Compression Ratio down to pump gas level

Originally Posted by BKbroiler

I have a 383 in my 77. It has 13,000 miles on the bottom end with over 330 quarter mile passes on it as quick as 12.18 and 110 mph. It won't idle at 550 but it will at 800, in gear (TH350 with 3K stall). It uses my original L48 block, bored .030 and an Eagle cast steel crank with the original connecting rods with the big ends resized and ARP bolts. I have JE forged pistons with about 9.7:1 CR.
I have iron Vortec heads with a lot of work in them. If I was building this now I would go with some type of aluminum heads. Cam is a hyd roller with Morrel lifters (I splurged on those.) Specs are 225/232 with .535/.550 lift at 112 LSA.
It has an RPM air gap manifold and a Lars Qjet.
This combination has excellent street manners. It doesn't run hot, doesn't detonate, starts easily hot or cold.
It has excellent throttle response from idle up to 5,800 rpm shift points.
You can't go wrong with this type of combination, and it is cost effective too.

Originally Posted by JC 1975

I just finished my 383 build and from my research, this was about as big as I would comfortably go with a stock 350 block.

Couple of important important pieces missing from your puzzle.

1) what’s your budget?
2) what do you plan on doing with it?
3) how much power do you want to make?

If you want a smooth idle and power, well you’re either going to have to go large displacement $$$ or turbo/supercharger $$$ or…. LS/LT swap it.

Blueprint has one of the cheapest 396’s you can buy @ $5,720 for the long block, but it has a 230 @ .050 cam on a 110 LSA so it will have some lope to it. My buddy has one of these so I can confirm it doesn’t have a smooth idle.


The other option is maybe you can have a custom cam made for your engine with very little overlap and a wider LSA???

Originally Posted by gkull

I quit building 3.750 strokers for 383 when I realized that for the same price you could buy the high end all forged 6 inch rod 3.875 rotating assembly kits. My first 396 was just the longer stroke and I used everything else from my solid roller 383. I could tell the difference in power even though I only gained @ 13 cubic inches. The torque was impressive. I use .027 Cometic MLS gaskets with -7 cc pistons to get @11.2 C/R. I learned a long time ago that with enough cam you can get your DCR down to allow your engine to run fine on our local unleaded premium. Heads are the utmost importance when you have long stroke, small bore, and relatively small valves compared to it's bigger BBC brothers. So I have used both AFR 210 cc and Dart racing 227 cc on my 383 and 396 motors. I kind of settle in on the AFR 210 for my 396. You can look up head intake port CFM of flow to potential HP calculators. AFR 210 heads are something like 314 cfm. You will also see that you want to lift the valves as high as practical and keep it open as long as possible at the higher CFM of flow. That's why I use custom solid billet steel roller cams. My third solid roller was the best for 383 and 396 when combined with 210 cc heads and a Weiand team "G" single planes and a 1/2 inch 4 hole wood thermal spacer. 236/242 112 and something like .644 and .664 lift. I also had the cam ground 4 degrees retarded when compared to the equivalent Comp Cams Extreme grind solid roller. I found that I had a power band over 3500 rpm wide. It was a wonderful road racing motor when combined with a 5 speed and 4.11 rearend.

Oh, my idle is more like 1050 or 1100 rpm and back when I had a 3500 stall 9.5 inch 700R4 it had negligible rpm drop putting it in gear.

Aftermarket blocks like the Dart SHP with the 350 crank main bearing size then become 415 ci with the 4.125 standard bore.

Originally Posted by JC 1975

Very familiar with CA smog. What year is your Vette??

Again, I would find a cam with little over lap because it would not scavenge as much, thus the engine will burn cleaner. You might also try fuel injection and lean it out during the smog test to get a better reading.

https://www.enginebuildermag.com/201...-back-session/

The cam is the key, not the displacement.

This marine cam from Comp only has 49 degrees of overlap.

https://www.compcams.com/xtreme-mari...all-block.html