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What to do with my Stock 400 sbc? Advice please...

Dog House

Well-known member
Joined
Oct 27, 2009
Messages
127
Location
Minnesota
Corvette
1989 Bright Red Coupe
Hello all, I’m looking for advice on what to do with my stock 400 W/HSR. I’d like to cam it and put better heads on it but not sure what to get. Not looking for a race engine just a faster street car with a little thump from the cam. :D

The car:
89 Coupe
Stock 400 sbc
Stock 997 heads 76cc
Holly Stealth Ram (stock TB from L98)
Bosch III’s
Lingenfelter long tubes
True dual exhaust (no cats)
Flowmaster series 3 mufflers
Dana 36 W/252’s swapping out with Dana 44 W/343’s or 345's don't remember off hand which it is?
700r4 Auto
 
You gotta be careful with 400s because of their weak connecting rods and low tolerance for running hot. You need to keep the rev limit below 5800 rpm and you need to make sure the engine cools well with a 180° thermostat.

I'd do two things to the engine...

Put on a set of L82 Corvette heads, mildly ported and fitted with 2.02-in intakes. Install a mild hydraulic roller cam with good pushrods and the correct valve springs. Keep the rest of the mods you have but have someone help you with an injector selection and custom calibrate the ECM to match the heads and cam.

Lastly, don't go to the 3.45 ratio and the four-speed automatic. You already have a 3.06 low gear and you'll do nothing but spin the tires with that short an axle ratio. The 3.07 ratio in the D44 will work better unless....you're, also, going to put some really big tires on the back and accept a fair-sized hit to your gas mileage.
 
DOG HOUSE!

Long time no post... Last I remember you were puttin' that 400 in! Or was it trackin' some fumes underneath?
 
DOG HOUSE!

Long time no post... Last I remember you were puttin' that 400 in! Or was it trackin' some fumes underneath?

Schrade, nice to see you too. :w Glad to see they still let you hang out around here. :beer
Have any constructive advice for me on heads, cam other than what Hib suggested?
 
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Schrade, nice to see you too. :w Glad to see they still let you hang out around here. :beer
Have any constructive advice for me on heads, cam other than what Hib suggested?

I'm workin' hard on a lockup here, like at CF (but that was for pokin' fun at blood n guts posts, and death and gore garbage in CFOT. THat's all they have, and it's kind of disgusting). You saw it - "I said let's see the bullet-riddled dog", or the blood comin' out of the tourist at the Jap Olympics HUH??? THey don't have lines to cross, they have circles around their pet posters...

ANYhow on your mods here, no Sir there DogHouse - sure do not. Aftermarket parts and heads I don't know much about. Only OEM operating parameters, and tune / diag's procedures / specs, etc... Don't know what to tell ya' there...
 
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Just make sure you got good fuel pressure, no leakdown static fuel pressure, good dynamic fuel pressure (motor running vac off, AND ON FPR), good balanced squeeze in all 8 holes, basic stuff FIRST... and no vac leaks, and properly routed SP wires...
 
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