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Hey guys, i just bought my 400 from my neighbor and i need to get it in the machine shop asap. I am getting the motor totally rebuilt and i am looking at going with a .030 bore out. My question is, is there a rod and piston set up that will get me a higher compression ratio than maybe a regular 400 set up, ive heard they make a rod and piston set up that has the connecting rod placed higher up into the piston for more compression??? ive babbled on enough now, let me know if you guys have any ideas or advice, youngster hear:thumbsup:.
Thanks,
Wally
 

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Rods don't change the compression, if they're chosen right. Wrist pin height in the piston is dependent on rod length since there's a specific "height" to the block, from the crank centerline to the deck. ½ of the stroke, plus the center-to-center rod length, plus the pin height from pin center to the "top" of the piston, plus the deck clearance, must equal the "height" of the block. Which is 9.025" give or take a few in the SBC. Stock deck clearance is about .025", so rotating assemblies are almost always 9.000" tall, except for "rebuilder" pistons (ALL cast, MOST hypers, and SOME forged, specifically including TRW and SpeedPros) which have the pin an extra .020" higher in the piston, which lowers the piston by .020", meaning that any of those cheaper ones will be about .045" below a stock deck at TDC.

If this has the stock 400 heads, throw them away. They came with the worst of the worst of the really bad 70s smogger garbage, like 882 or 624 castings. Get a set of 64cc ones. Vortecs wouldn't be a bad idea.

Until you decide what heads to use, it's impossible to determine the CR.
 

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I use to run the better stock heads 1.94/1.6 valved,and home ported them also. At 9.5:1 with 5.7 rods, and a 280H CompCam it went [email protected] with 2.73 gears... lots of torque for the street.:yes:

The pistons are TRW forged (# L2352-30).
 
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