chevy 400ci V8

yeah, I lost a bottom end on a 94 2500 I had from an intake manifold antifreeze leak.

the intake bolt holes do line up, the bolts just won't go in.

the later heads still bolt on the early blocks, the intake bolts are a steeper angle on the engines with valve cover bolts in the center of the cover instead of the traditional 4 around the outside guess it's the genII.
there are carbureted manifolds available for them in the aftermarket.  
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They must of changed it with TBI in 87 then too. I never did a TBI/MPI to carb conversion because I would not. Not because I hate carbs but because I like the easy cold start ability of the FI models that do not even require throttle to start. I can reach in door and without even getting in I can fire up my MPI plow truck or TBI burb and let it warm up a bit while I am dusting it off whether it is 20 above or 20 below, it starts instantly and runs smoothly. (this is what I like most about FI)  

I use the fast burn heads on the early blocks, they usually stay carbureted, I rarely have trouble tuning and getting carbs to work properly, can't say I never have to mess wtth then though.

no doubt the injection is better in the cold and changing altitude.  
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I am thinking about putting in flat top pistons in my 400 in my 78 blazer since i know it has those low compression smog pistions that give bad gas miliage and bad power, what do i have to do to install the flat top pistons, i mean how do i know waht the commpresion ratio will be, what kind of gas to run, will the valves hit or not, are there any other mods i need to make?  
solid axle chevys cant be beat
78 K5: 350 V8,700r4,np208, 8 lug D44 4:88, 14 bolt 10.5 4:88 with detroit locker and 35 inc parenelli jones dirt grip tires

no worries on the valves unless you go so big with the cam it won't idle or you start messing around with the rocker ratio, the cr with the flat tops will depend on the cc of the heads, keep it at or under 9.5 and use high grade fuel.

you can figure out the cc cr from summit or jegs catalogue  
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Many to not realize how bad 87 octane can hurt you in overall power and MPG. 87 was "designed for CR's of 8.5 to one and less. In higher CR engine they get it to tolerate it by mixing EGR gasses and retarding spark. Knock sensors have gotten so good on modern engines (quelling knock before you here it) that it keeps owners in ignorant bliss while stealing power and MPG. Realistically for proper spark curve you need 89 octane for 9 to maybe 9.5 CR (on a standard day)and 91 to 93 above that (in winter octane need decrease a bit and increase in summer) If you have a GM TBI motor you will find that it responds very well to advancing base line timing from TDC to about 8BTDC or so (if you live at high altitude you can advance it even more) and using better fuel (it is set to TDC to tolerate 87 octane, not because it is best setting for engine) YOu will see a power and MPG increase. One warning here, if you do this, do not fill it up with 87 because it will rattle badly at times but you will find it cheaper to drive on better fuel too because it will use less of it!  

for what it's worth i had an 86 chevy 1 ton single wheel 400, sm465, np205, 8" lift, 38" buckshot mudders, that i could wind to 7500 rpm on a daily basis. i didn't build the motor or the truck but it would scream!! never hurt a thing! i like 400 small blocks and i'm sure if their built right they can reliably turn high rpm.  
STAND ON IT!!!

7500? the tach must have calibrated for a 6cly lol. wow....
we're talkin foating valves and bent pushrods there with stock springs, the peak power is clear down below 5000 unless it was toyed with.  
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I used to wind my mostly stock 400 up to 5000 RPM often, a couple times close to 6000 RPM.  7500 RPM takes a lot of performance parts to make it live.  

like i said i didn't build it but it was built. it had to be pushing 450+ hp. it was the fastest vehicle i've ever owned and i've had some fast cars. my buddy in his ford lightning ran along side me down the hi-way at 130mph! now you tell me what kinda power it takes to move that truck at that speed. but i promise you every time i climbed the mountain i held 3rd gear at 7500 rpm at 75 mph.  
STAND ON IT!!!

I could have alot fun with you, LOL I love that power also  
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do you mean have fun like four wheelin or are you messin with me?  
STAND ON IT!!!

btw did you notice i'm not a NEW user anymore? woohoo!!  
STAND ON IT!!!

dude, wheeling,
I gotta keep ya wondering though.  
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GM1tonOfFun:
I used to wind my mostly stock 400 up to 5000 RPM often, a couple times close to 6000 RPM.  7500 RPM takes a lot of performance parts to make it live.

I raced a few 400's many many years ago and 7500 RPM is not possible without some exotic after market parts. (I have see a few blow a little over 8000 with some very expensive aftermarket parts) It will come apart before then otherwise. One of the big reasons for a 350 crank in a 400 block is that it allows for longer and stronger factory or aftermarket rods and better rod angles and reduced piston velocity/inertia stresses on crank shaft, rods and pistons.