Suggestions on my 400 build

[Dirka]

This might be a no brainer question, but I always thought it best to get a 2nd opinion...

I have a 400 motor (395109 casting # If I remember right,  any who I know it's the high nickel block) I currently have it torn down to where just the cam and bottom end are left in the block. I went to compcams and gave them my information have a cam suggestion from them for what I'm looking to do.
http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=K12-210-2
As of now I know I need a new intake manifold to go with my 4brl carb. I'm thinking the dual plane performer intake from edelbrock and I will get new exhaust manifolds bc the old ones are rusted stock. I'm looking to stay around $2,000 right now on this rebuild. So my question is this, should I spend the bulk of my money on new bottom end parts to go with the cam and future upgrades on the top end? Or since this truck is mainly a workhorse for me with towing and winter driving mainly in the first several years on ownership planned that I should just keep it as it is, and do the Heads, intake, exhaust mani's and exhaust system to go with the cam?
thanks

[thirsty]

My opinion is too go thru it all or don't do anything. If you put in a new cam it will be hard on the old bottom end. Do everything and don't look back. Just my $.02 though.

[gto109]

I agree with thirsty and just rebuild the whole thing.  You will be further ahead in the long run.

[Dirka]

Where's the best place to start looking at rebuild kits?

[gto109]

northern auto part,s summit racing, jegs, honest Charlies.

[Fairlane514]

If you have an old bottom end and put new heads with a fresh valve job, it can cause problems with piston rings sometimes. I would also keep an eye out for used parts, such as an intake, headers, roller rockers.

[78 Chevyrado]

What mixing old stuff with new does, in a nutshell is it stresses old parts that were ok with other new parts, but the new parts put extra stress on the old parts.

If you do a compression check, and everything looks ok, and the cylinder pressures are relatively even +/-10%  you can get away with a new cam.  HOWEVER, to put in a new cam, in my experience, you need new heads or to have the existing heads rebuilt, or you'll end up with a burnt valve or something in 15k or so.

If you do buy new heads, they MUST have the steam holes drilled for a 400.   Probably 98% of the famous "400's overheat"  fiasco is that people put head on there without the steamholes.  I had a 400 TBI in my 87 and It's the best engine I've had in any squarebody I've owned.

Here's some pics for motivation.  Stock built 400, with 87 TBI modified to fit it.  Ran a th700R4 behind it and 2.73 rear gears.  got 23MPG out of it, on the highway.  It turned something like 1700RPm at 75MPH, and didn't downshift at every molehill like the old 305 did.  matter of fact, it rarely unlocked the TQ converter, even over the hills of TN from Chattanooga toward Nashville.





400 fun!  ha! 




I don't and probably won't have a 400 in my truck because, I cannot find one...  otherwise, no other small block can touch it, with equal mods, unless you want a smaller engine that turns 8000RPM.

I love 400's  Only other engine I want besides a chevy 400 is a caddy 500.  if i don't get one of those, I'll probably get an EFI LS-whatever engine, so i don't have to tune it so much.  only a 400 or 500 is worth the tuning a carb to me.   

[gman6762]

spend the bulk of your money on heads the smaller the cc of the chamber the more compression you have but im also with thirsty its cheaper in the long run to rebuild it all. i have over 4k in my old 400 small block its bored .60 over and dome top pistons 1.6 roller rocker  brodix heads with 216 valves im running a 12.1 compression ratio. producing around 480-530 hp it held up good andi had more money in gaskets than most had in rebuilds but the head gaskets were about 175 a piece they we cosmetic turbo car gaskets. it was all good till i melted a piston down):and scared the cylinder wall. but now im swapping to a ls motor serious power just do research and make sure that what you really want to do before you spend the money..