Thread: Coolant in cylinders; fresh 400 sbc build

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Originally Posted by Bigbzc

Excuse me for being idealistic. I will just find some cheap heads that can be reworked and get this thing together. That was what this thread was suppose to be about in the beginning. Hoping maybe I might even find someone who will trade some unworked heads for mine

Bigbzc,
No one is going to criticize being idealistic, but you're being challenged to be realistic in your build vs just spending money and being unhappy with the results. Tech has spent quite a bit of time going into a lot of detail about how you can build for your situation and not destroy the engine via detonation. The days of old are gone - fuel is crappy, oil is crappy, and everything costs arms & legs. Pat's pointing out that you're going to spend quite a bit of good money bringing used stuff up to snuff if you choose to go that way.
Tech's last post very clearly says "If it were my engine...." No one is telling you what to do here, but you've got a combined wealth of experienced guys (not me....) who are trying to not only give you good advice, but lead others that are following this thread down a path that leads to smiles not frowns. Good luck on your build, whichever way you choose to go.

In the late 80's I pulled a stock 400 out of a 72 Caprice Estate wagon, replaced the rear main seal, stuck in an old 30/30 Isky solid lifter cam, an Offy 360 intake with a 650 Holley DP, a set of Hedman headers, a 454 flywheel, and had a shop in town build me a 3100# pressure plate and the best clutch disc they sold and stuffed in a 62 1/2 ton Chevy truck. It ran on 87 pump gas and it wasn't the baddest thing in town, but I did surprise a few folks. Don't try to reinvent the wheel.

i machine parts and build engines all the time every day. on a set of old small block heads with all new stock parts .valve intake and ex .springs. seals . guids . ex seats . hp valve job . mill .and boil out and mag its not hard to get to $500.

If I was to fix your heads----first I would clean, then weld up those slots for the water below the spark plug, resurface, new guides, then new hardened seats, followed by a radius valve job, screw in studs,cut spring seats, assemble with longer valves/springs and pushrod guide plates---I would charge you well north of $1000 to do that and you would get no guarantee.

I have never had anyone unsatisfied with and valve train work I have done and they usually send there friends with there stuff. Pat charges far too little for what he does but I guess Michigan is a different market.

Originally Posted by jerry clayton

If I was to fix your heads----first I would clean, then weld up those slots for the water below the spark plug, resurface, new guides, then new hardened seats, followed by a radius valve job, screw in studs,cut spring seats, assemble with longer valves/springs and pushrod guide plates---I would charge you well north of $1000 to do that and you would get no guarantee.

I have never had anyone unsatisfied with and valve train work I have done and they usually send there friends with there stuff. Pat charges far too little for what he does but I guess Michigan is a different market.

Now there is an idea I thought of too! Welding the part of the ports and shaving them back down to the head surface. You see, these heads are already built with new everything, valve job and all. They were just done with a 350 in mind because that is what the dude was gonna put them on until he found out that the 350 block was cracked. So he got the 400 and was gonna put them on it. Thats where I came in because he got too sick to finish and sold it all to me.

So, maybe I should just shut up, weld these suckers and get her back together!

On another note, I never put Techs advise down. I put some other guys who really didn't seem to read the whole thread to see where I am coming from. I simply asked Tech what he thought of my idea of E85. I have found a way to do it quite simply it seems too, but if I can just fix the problem that sits right in front of me, thats what I'm gonna do

On second thought, there isn't enough surface left to shave the warpage the welding would cause

not just any one can weld iron the heat zone can get hard as glass and you will never cut it with a tooth cutter mill .you may cut them with a stone wheel or segment wheel and the guy may bitch you out really good along with a $$ for the surface job or tell you to pound rocks.i would plug them with iron plugs if there is meat there to run a row of plugs two hours should be done.

I looked up "350 chevy heads" on the national craigslist search and found a bunch of stockers starting at $40 with some that had a fresh valve job for $100.......why not use the correct heads instead of compromise 305 casting? Vortec heads in stock form are pretty cheap too, I have seen those under $200 a set....drill the steam holes and drive it.

Originally Posted by robot

I looked up "350 chevy heads" on the national craigslist search and found a bunch of stockers starting at $40 with some that had a fresh valve job for $100.......why not use the correct heads instead of compromise 305 casting? Vortec heads in stock form are pretty cheap too, I have seen those under $200 a set....drill the steam holes and drive it.

Thanks I'll check it out

I just looked again at CL nationwide......there are Vortecs for 150.....

BEWARE Real "Vortec" heads are easily identified....they have only four intake mounting bolts per head. They have center bolt valve covers ONLY. Vortec heads were put on 96-2001 GM 350 engines installed in trucks and vans. Vortec heads are the best flowing stock GM heads that will fit a small block. The intake gaskets are unique to Vortecs.

A vortec head will require a vortec intake manifold such as an Edelbrock 2106.....inexpensive manifold. The heads also require the proper guided rocker arm.

Originally Posted by Bigbzc

Thanks I'll check it out

well that sound s good but getting out of a machine shop for a $100 with done heads would have to be very nice heads to start with and you still would not get out of my shop brake down tanking them and mag job + a valve job puts you past $200 thats EZ to do.you have to ask your self what your not getting for that $200 set of done heads on craig list? . i have head casting for 350 chevys that are good cores not hard to find its the labor to do them right that cost

L31 Vortecs are 64cc's, too small for a 400 cid motor, SCR too high.

I haven't kept up with small block stuff, but aren't there some heads out there (salvage yard) off a 400 or are they scarce/no good/need too much work?

Originally Posted by pro70z28

I haven't kept up with small block stuff, but aren't there some heads out there (salvage yard) off a 400 or are they scarce/no good/need too much work?

I think most 400's came with small-valve 76cc chamber heads that didn't flow really well. They were not intended to be a performance motor, but rather a mule motor to pull heavy sedans and wagons.

i have seen 400s with a cam and intake change that flat ass ran... go back and read post 72 he did say he was keeping this engine stock so why put him thru a knothole backwards ? just put some big CC 350 heads on it with seam holes and be done. like someone posted on back on 72 ??