Thread: 406 vs. 377??

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alright.. im in the begining stages of a 400 build and im just still questioning which way to go?? im not doing anything wild just the good old 800-900 dollar rotating assys. block is a two bolt 509 casting. going on top will be the top end that is on my 283 currently.. * GM Performance vortec heads, 1.5 roller rockers, *upgrading to screw in studs and possibly a bit of pocket porting if feeling greedy. and a performer rpm manifold. just curious on which way to go .. 377 or 406?? going in a truck 3800+ lbs, 700r4 trans and 4.10 gears with a 28'' tall tire

I'd go with the 406 cuz TQ is what a truck needs & TQ = Cubic inches.... jmo Bill

5.7 rod or 6.0? also what kind of pisons? flat top? domed dished.. that stuff.. ? wanting pump gas and 64cc heads

Tim, go to Mopar Performance Parts High Performance Racing Engine Parts & then click on 'manufactures' {left side of screen}, then click on 'Ross Racing Pistons', then scroll down & click on 'compression calculator'. Fill this out {bore, stroke, gasget thickness, head cc's, etc} & it will tell you what pistons you need with 64 cc heads to get the compression you need for a pump gas motor {I'd guess you'll need dish or reverse dome}. I believe you want around 9 to 9:50 to 1 w/ iron heads & 9:50 to 10 to 1 w/ aluminum. But you also must consider the quelsh {spelled wrong} area & for this you'll need someone with more expertise than I have {area between the top of the block & the top of the piston when at top dead center}. Some of the more knowledgeable folks will have to help you on that. Also the size of the cam comes into play on Compression because a larger cam 'bleeds' off compression & visa versa. Also you need steam holes in the heads to run on a 400. Hope this helps ya. But again, you need someone with a little more knowledge than I.... Bill

ps, oh, also some of the web sites for pistons manufactures can be of help. Like the J & P pistons site {which is also the SRP site}....