ok, what determined how far you added cubic inches?
I see a lot of 383s a few 396s an a couple 427s+

money? longevity, street manors?
at what point does offset wrist pins, other trick parts are needed?

will a 427 idle as low as a 350 can?

looking to stroke but cubic inch itis is messing with my wants.

any and all opinions, experiences wanted about best overall cubic inch size
to go for.

need smooth 550 rpm in drive.
thanks

 

You can push a 350 block to 396, and a 400 block up to 434. Displacement equals power, the bigger the engine the more power they can put out.

Idle quality is all about the cam, not the displacement. There is no problem getting decent idle and good power with modern cams.

The 383 is popular because of cost per hp. A 400 hp 383 isn’t much more than a rebuilt 350 these days. A 434 isn’t going to be cheap.

 

so what did you choose or what do you want?
looking at parts, a 383 crank is same as 396.
so are rods, pistons are close.
and I realize cam affects idle.
thanks for posting.
looking for thoughts and choices on ci sizing

 

I went with a 383 crank, I was concerned about rod to cam clearance.

I also wanted to keep my compression ratio around 9.5:1.
While plugging numbers into calculators and researching kits I discovered it's easier to keep the compression low with less stroke.

 

I also used a calc for cr and was surprised how little it added.
about .35 in my choices.

 

I went 383, partially due to parts availability and it makes what I wanted for HP. If I could have any parts I wanted without waiting 6 months to a year, I would go 396. It depends on your goals, I just wanted a street rod that would make lots of tire smoke and didn't want to wait a year for a motor. The parts situation looks to be getting better, but it's something to consider.

 

I remember covid did a number on parts.
I didn't even think about it now
thanks for the heads up.

 

that idle speed is about GOOFY.

 

I believe you can build a 427 or even a 434 with good street manners.
I think you answered one question for yourself, that it won’t cost much more to build a 427 rotating assembly over a 383.
Check on possible additional machining cost to the block for clearance and different type or different manufacturer’s rods to block clearance issues.
There are other things to consider that could change between building a 383 or 427, such as the oil pan to rod clearances.

 

Depends on your goal. For me it is all about the stealth look of a factory type 1965 365 h.p. engine. So I am going 383. Anything more than that and I would have to upgrade the original type carb for a factory 365.
If this is not your limiting factor then I would say go with a 396 with headers. If I was not concerned with the above I would do this to my 1965 and add factory 1965 396 emblems to the car.

 

Just for the record. Stock gen 1 SBC'S are kind of limited to maximum stroke of 3.875 with a 4.030 bore is @396 ci. Beyond that and the pan rails to oil pan get so thin that you would have oil leak issues. You also have to use stroker oil pans that are clearanced for 3.875 cranks and 3.750 if you are using large ARP bolt rods.

Dart SHP blocks say maximum of 3.750 strokes. It takes about half a day to machine clearances for 3.875.

Racing blocks can get to 4.125 stroke and kind of max out at 454 SBC'S without any clearancing. Like my maximum block bore is 4.200 and my 4.00 crankshaft.

 

My thoughts would be 383 first so I could still have the block machined to go bigger when I wear that junk out. Honestly though im waiting for a 406 project to come along at a good price.

 

You are not looking at it correctly. Bearings and rings ware out. Not crankshafts. Like my 3.875 motor and 4.00 stroker motors have had 4 rebuilds each with only the 427 getting an overbore.

 

A 383 is easy to build now and as far as you want to go with a stock block without stroke clearance.
Keep the camshaft in the 210-215 @ ,050 range and the idle will be pretty smooth....this is with a Hyd. roller cam.
All modern shelf pistons have a .100 wrist pin offset.
If you use a modern head.....you can run 10.5 to 1 on the street with 91 octane fuel.
Keep the head intake port size small 175-180 cc's......I like the Dart 180 Pro-1
The Edelbrock Performer EPS is an amazing piece.....it works well past 400hp and fits under the hood of C3's with a little finesse....

Jebby

 

some good info. thanks guys.

I was hoping to keep it general and hear from people who "been there done that"
to see what was picked and why?

one constant position from new owners is, what can I do for more power?

hoping more people will join in.

 

I’m the middle of a 396 roller build. Going with FI-Tech. shooting for 500/500 coming off the dyno. Using a deeper pan to accommodate the stroke. Doubt this one will idle at 550.

 

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???

 

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.

 

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.

 

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?