So here's and engine shot of my motor, 400ci Small Block. I plan on building this motor, but it's not happening until winter, when i plan on a complete restoration of the entire car. I want to begin planning now to get everything in order, because I hate last minute suprises.




So, if you know anything about 400's, how hard or easy this build would be, and what parts(Cam, Pistons, etc..) arte best, let me know!


mike

 

what are your goals for this motor? Will this be a DD, track car, or a mix of the two?

What tranny do you have in it currently? Is it in good condition?

Once you start making power, you will start to break things further down the drive train, like the tranny and rear end.

You will most likely need to upgrade one or both of those things when you upgrade the motor, a 4th gen rear end w/ posi and disc brakes will bolt right in place of the stock 3rd gen rear.

 

I will be running a Moser 12 Bolt Rear End, Beefed up driveshaft and a TH350 tranny with Stage 3 Shift Kit. Even thought my tranny I have now is good, im putting the other one in, because it is rebuilt with performance internals. I want to make 400-450 whp on motor. I'm also getting the frame reinforced this winter incase I want to go over the 500whp "frame-bending" limit. I want it to be a mix of the two, but I'm gonna have an extra beater car for when I have the Z28 apart this winter.

mike

 

400's are almost the same as 350's in aftermarket parts selection. Vibration Damper and flexplate are different. Steam holes in heads should be drilled for extended street use. Blocks are weaker. Bore walls are thinner. So have the machinist carefully check for cracks and wall thickness.

All companies make pistons for 400's. Probably should go with forged.

What's your budget on the motor? AFR 195's in yours? Dart? Brodix?

Do you plan to replace the crank and rods (with good forged ones)? Ya should, definitely if you're considering 500whp. The stock rods are short and junk for this power level (and any power level). The crank is old and unreliable - some live with them, some lose the engine with them.

450 fwhp with good heads (like older AFR 195s) and exhaust is doable with as small as a 230/230 @.050" and about .550lift; hydraulic, on about 10.5:1 cr; Dual plane RPM and 850cfm carb. Back it up with a pretty good exhaust. That would be fine for daily driving, too.

450 rwhp... AFR 195 eliminators or 210's or more; ~ more than 242/242 @.050" solid, >11:1 revving to 6700 or more. Single plane & big carb. Good long tube headers, very large or dual exhaust. Splayed 4 bolt conversion on a good block (I'd go for a Dart Little M though). It'll be a little nasty on the street. Children will hide behind their mothers. Dogs will bark, then run away. Prius owners will call the cops...