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How much lift will the 383 allow?

RRSweden

RRSweden

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I have the heads, crank, and cam out of the block, so I thougt, instead of put them back to measure, I'd ask here.

I'm scouting for a new camshaft and wanna know how much lift I could have before the valves hit the pistons.

383, stock crank, 906 heads w. stock rocker arms (believe they give a 1.5 lift ratio, am I right?)
 
It depends upon which pistons you are using, and how far Below the deck they are. I built my 383 with KB400's that are .020 in the block. I used a steel shim head gasket .21 with 906 heads.. I have a 513int 538ex lift camshaft in mine, with no problems...
 
The KB400's I used have a 6cc positive dome..They are above the deck.. but the flat area of them is at .020 below deck.. You really need to measure how far down in the block, your flat tops are, and know what head gasket you will be using...
 
RRSweden said:
oops. Forgot to write that i have flat-top pistons
Click to expand...
Stock flat tops? Most replacement pistons do not even come close to what the originals did and compression heights were different depending on year. Also, stock replacements and many other aftermarket piston manufactures advertises what the max compression could be if everything was done to try and get there. Only way to buy pistons is going by the compression height of it....
 
stock 10:1 flat tops won't take a lot of lift and neither will stock iron heads. valve timing also comes into play. the saving grace is that 383's don't need big cams to perform well. something like a comp cams 280h magnum should be pretty safe for stock pistons and heads. the KB pistons do have valve reliefs. a lot of 383's are getting built with 8:1 pistons which will give more piston to valve clearance but won't perform as well as the higher compression pistons.
 
I have been looking at that cam, lewtot184.
But I've hesitated a bit cause of the description:

"Designed for hot street/strip cars, these COMP Cams Magnum series cam and lifter kits require a higher compression ratio, rear-end gear ratio, and stall torque converter than stock. With a very aggressive profile, these cam and lifter kits provide maximum top-end performance for your high performance car."

From my calculations I have between 9 and 10:1 compression, and 3,23 rear end gear.
You think I'll be fine with this cam? My goal is to build the engine a bit, but not too much more agressive than stock.. Say my target is about 350hp.. (my first engine build)
 
Measure, measure, then measure again. Here's some specs on the 383 I just finished. .030 over, speed pro forged aluminum flat tops. 019 in the hole, .041 head gasket, 440 source stealth heads, stock rockers and push rods, comp cams xe268h-10 cam (.477/.481) , 9.44:1 compression ..... intake valve to piston clearance .057, exhaust .163 .... engine runs great !
 
Last edited:
RRSweden said:
I have been looking at that cam, lewtot184.
But I've hesitated a bit cause of the description:

"Designed for hot street/strip cars, these COMP Cams Magnum series cam and lifter kits require a higher compression ratio, rear-end gear ratio, and stall torque converter than stock. With a very aggressive profile, these cam and lifter kits provide maximum top-end performance for your high performance car."

From my calculations I have between 9 and 10:1 compression, and 3,23 rear end gear.
You think I'll be fine with this cam? My goal is to build the engine a bit, but not too much more agressive than stock.. Say my target is about 350hp.. (my first engine build)
Click to expand...
another option with the 3.23 gear is the xe274. the xe 268 would give very good low end torque. the howards cam #720141-12 might make a nice compromise.
 
65-440 said:
Measure, measure, then measure again. Here's some specs on the 383 I just finished. .030 over, speed pro forged aluminum flat tops. 019 in the hole, .041 head gasket, 440 source stealth heads, stock rockers and push rods, comp cams xe268h-10 cam (.477/.481) , 9.44:1 compression ..... intake valve to piston clearance .057, exhaust .163 .... engine runs great !
Click to expand...

I guess I'll do that. Your setup sounds quite similar to mine. How's that cam working for you?
 
RRSweden said:
I guess I'll do that. Your setup sounds quite similar to mine. How's that cam working for you?
Click to expand...
working really good. nice idle and pulls hard ! i originally purchased the XE274 grind but was quickly talked out of that one. A good friend of mine has that in his 383 and hates it, i did some research and apparently something about the short stroke of the 383 makes that cam not the best on the street. I went with the XE268 and honestly think it turned out perfect. Matched it with a 2500 stall converter and it has very good street manners. Even has a better idle than i was expecting, i thought it was barely "lope", but i was wrong, sounds mean at idle !
That same friend of mine is changing his XE274 and going with the XE268 like i have ...
 
65-440 said:
working really good. nice idle and pulls hard ! i originally purchased the XE274 grind but was quickly talked out of that one. A good friend of mine has that in his 383 and hates it, i did some research and apparently something about the short stroke of the 383 makes that cam not the best on the street. I went with the XE268 and honestly think it turned out perfect. Matched it with a 2500 stall converter and it has very good street manners. Even has a better idle than i was expecting, i thought it was barely "lope", but i was wrong, sounds mean at idle !
That same friend of mine is changing his XE274 and going with the XE268 like i have ...
Click to expand...
Thanks!
Sounds more and more like that's the way to go then..
 
I'm looking for that shaft, but I don't know if it's maybe out of production or something... I live in sweden, so I maybe don't know where to search for it.. I've looked at summitracing and jegs , but they don't have it...
Where do you guys shop? Im gonna order a bunch of stuff.....

Just foud it in a kit with lifters on jegs eBay for a decent price.
But still, it could be interesting to get some good links from you guys to good american sites for parts.
 
Last edited:
RRSweden said:
I'm looking for that shaft, but I don't know if it's maybe out of production or something... I live in sweden, so I maybe don't know where to search for it.. I've looked at summitracing and jegs , but they don't have it...
Where do you guys shop? Im gonna order a bunch of stuff.....

Just foud it in a kit with lifters on jegs eBay for a decent price.
But still, it could be interesting to get some good links from you guys to good american sites for parts.
Click to expand...

Do you know Moparshop in Germany? buy most of my parts there.
 
With the XE268, edelbrock rpm, would a Edelbrock 600 be to small on the 383?
also with some sort of older headers?
 
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