[383_Gladiator]

Hey guys, new here. was on another forum but they take way to long to reply and not enough opinion (same 2 guys answering)

My 383 will be going into my chevy K20 used for mud bogs and off-roading but still street driven.

383
Scat crank
AFR Eliminator 195cc runner 64cc chamber
9.5 compression
Weiand dual plane stealth intake
750cfm holley carb
comp cams X4262H hydraulic flat tappet cam
262/270 duration seat to seat- 218/226 @ .050" lift
lobe center angle 111 intake centerline 107
valve lift intake: .462 exhaust: .48
1.6 roller rockers
hooker competition headers

desktop dyno shows 420 hp and 472 TQ

will be sitting in front of a SM465 4 speed and 4.10 axle ratio

Any suggestions? thanks

[Custom10]

Just one thing to add here as I will leave the build instructions to the experts. Shooting for 9.5 SCR with 64 CC heads will require a dished piston, if you are so inclined look at the KB hypers that I used on my 383 at -18 cc that should get you close with around 0.040 squish. Going with these slugs will require close attention to the ring gap settings and get them in there tight at no more than 0.002 piston to wall clearance. My 2cents

PS welcome to HotRodders...don't worry you will get some expert input here for sure, some friendly advice...careful not to bash other forums or folks you never know who's listening

[383_Gladiator]

Haven't bought the heads yet, i could go with the 75cc chamber if it makes it easier.

[Custom10]

A good place to start for determining compression ratio is this site that you can plug in your numbers and it will calculate SCR and if you know your cam specs namely intake closing point you can get DCR as well. Those heads you had in mind at 64cc are OK but you will be asked many more questions which may reveal that they are not a good fit, too early to tell and I am not the one to make that call, you amy be asked many questions by those in the know, have some fun and take your time with your build good luck.

http://www.kb-silvolite.com/calc.php?action=comp

[383_Gladiator]

hmmmm i know most of the numbers but not gasket thickness and bore as well as deck clearance. this motor will be built by an engine builder, im sure he can easily get 9.5

[Silverback]

"standard" head gaskets are usually around .040" thick (most fall in the .035-.045 range), and factory they put the piston about .020" in the hole, but some aftermarket pistons are setup to sit a little bit higher to make up for that or your machine shop might deck the block lowering it.

Assuming not to much of that has been done, you should be able to get into the mid/high 9's with a standard piston, OTOH, I'd probably be shooting for higher or lower than that... if you want to run on 87 octane, I'd want to get that down to about 9:1, since 4 wheeling can be a lot of moving slow with a heavy load on things, engines get hot and are more detonation prone than street/drag cars... Otherwise, if you're willing to run premium then I'd probably consider 10:1 or so to take advantage of the extra available power from the higher octane.

[ssmonty]

If you don't already have your block, I would get a OEM roller block, and buy a roller cam and gain about 35ft lbs/HP, and have allot more piece of mind against a cam going flat. At least thats what I get using Cam Quest just switching from flat to roller.
ssmonty

[383_Gladiator]

I have my block already and my crank. Had planned on running 89 octane. As for the cam ill have to see what's available in the size I want

[a1supersport]

A friend of mine ran a similar engine, 150-shot of nitrous, with a TH350/3000-stall converter, Dana 44 w/3.73's and 40-inch Boggers, in which he cut every-other "tooth". It was all in a IH-Scout frame, with no body.

The limiting factor might be your trans. Trying to shift up-or-down while in the slush is impossible, without your tires coming to a complete stop. If you're racing, you'll lose time. If it's just for having fun, you'll be fine.

Automatics are good at compensating for track conditions (dry/caked/mud/slush/etc.). For standards, once you're in gear, you're pretty much in that gear the whole run. Forget about power-shifting an SM465...I've tried that in my 3/4-ton running the 1/4 mile drag. Snapping the input shaft isn't a "beautiful" sound.

[383_Gladiator]

I've been running my amc 327 in front of a t-98/d20 combo so I know about the shifting. Very similar trannys and t-case. What I'm doing is using a 75 K20 frame and axles and putting the body of my 67 jeep gladiator on that frame

[farna]

To get higher lift??

[383_Gladiator]

Better availability and cheaper parts. Getting to expensive to try and keep up with old jeep parts. And this way ill have power steering and much better brake system. As well as stronger drivetrain