Im buying a 400 SBC, question about combo & what heads to use.

[Bipolar]

Yep, I'm buying a running 400-4 barrel small block from a 1978 C20 for $250... Its all complete & stock and has never been rebuilt/bored. Although its running I plan on doing a complete budget yet some what "HiPo" rebuild. I know... That's an oxymoron. Any way, I will most likely bore it 30 over unless its in extreme good condition but I plan on it needing it.. I think 30 over makes it a 406cid.. I really don't know much about 400's but im learning. I know they have steam holes in the heads, they are a Siamese bore block, which I hear makes it more ridged but harder to cool, & they have a short 5.560 rod. I plan on going with 5.7" or maybe 6.0" H beams & a set of Speed Pro forged pistons. Which length rod is better & why? Now here is the question I really wanted to ask...I can get the steam holes drilled locally for $20 in what ever heads I plan on using, so should I go with a set of Vortec's OR.... Aerohead Racing (AKA Indy Cylinder Heads) has a set of 1986 & Earlier, 65 or 76cc Combustion Chambered heads, with 2.02X1.60 Stainless Valves, & .525 Lift Springs, 3/8 Screw in Studs assembled and ready to bolt on for $369.00 with no core charge!! And for $150 more I can have the intake & exhaust bowls ported and polished.. Isn't the bowl area the hardest & most important part to do? I mean, I can do the runners, chambers, & gasket matching myself.. But I don't know which would be the better move. I read today that the Vortecs out flow the Edelbrock Performer RPM's at .500 lift! WoW! Maybe I should get a set of Vortecs and have 2.02/1.60 valves put in them and have'em ported and polished, but remember, this is supposed to be a "budget" build. Whenever I figure out which heads i'm going to use then I will have Comp Cams recomend a cam for my aplacation. So how do I know what heads will be best for me? Is this 400 SBC a good move or not? Any info or suggestions on the whole mess will much be appreciated wether its good or bad news.. BTW this is going into a 86 RX7 with a T56...Thanks guys!
PS... I know the Vortec's use a specific intake manifold but I have one from Professional Products that is a dual bolt pattern for either style head. I also will be using a Holley 750 double pumper with a aftermarket smooth, racing, main body.

[4348rd]

i would go with the vortec heads, edelbrock makes the intake

[Fenster]

On a 400 ci motor... Go w/ more than the vortec heads... and edelbrock TPI intake. You would be vastly dissapointed in the results w/ that combo IMO.

I know you say budget, but at least take the time/money to get the right parts first. IMO you should get some AFR 210 or 220 cc intake runner heads ($1500) and run a victor JR intake w/ an appropriate carb. That combo w/ a good set of 1 7/8" headers would really make an impressive combo, depending on the cam choice you make.

A 400 is a great setup. Not many original 400 blocks left, so you are stumbling across a hell of a deal for one. Figure w/ good rods/pistons, machine work etc you will probably spend at least $2k on the short block total. Trust me. Take the time to get a good set of heads. Thats where the power's at. For performance a set of stock ported heads, or even the vortecs will not perform where you want them.

[Enthusiast]

Id agree with Fenster. I built a 383 a while back and used the combo on AFRs website and that thing was a monster. I sold it to a buddie and he dropped it in his el camino and that thing will shit and get.

[Chris 96 WS6]

I agree stay away from the Vortecs...no way they will flow enough to feed a hi-po 400ci motor. Plus they're iron so that's like 50lbs of dead weight vs aluminum heads.

I would say look into Trick Flow's offerings.

[1970judge]

If your on a budget....save until your not on a budget and get dart pro 1's. For like 600$ and some change i put the pro 1's on my nitrous motor. I loved them and the flows were awesome on them out of the box. 215cc is damn good for out of the box and not paying too much. They put out 2.050/1.600 if im not mistaken dont quote me on it.

[five7kid]

The Vortecs would be fine on a mild 400. What determines whether or not it will be "mild" is the cam. When you call Comp Cams, the first thing they will ask is what you plan on doing with the end product. In an RX7, you won't need a whole bunch of power to get the thing moving, so "mild" is probably in order.

If you go with the Vortecs, I've never heard that larger valves do them any good unless you get into very detailed and professional porting. That doesn't fit with any part of your plan, so don't bother with larger valves if you go with the Vortecs. The dual-pattern intakes are terrible on Vortecs. Either get a Vortec-specific intake, or don't go with Vortecs.

I would be very careful what you consider from that head house. You could end up with a set of 882's- not worth the shipping cost, let alone $369.

I'd have to agree with the aftermarket recommendations. Power is in the heads, and attempts at saving a little money now typically results in spending more money in the long run to get the desired results.

[Bipolar]

Well its home now here is the specs..
Casting #3951509, 400CID, 2bolt main, 74-75 year, 2 frz. plugs....
At first I was pissed because I didn't see the ever so well known 3 freeze plugs and figured it would turn out to be a 350, but there was some made with only 2 freeze plugs and this is one of'em. The engine is really clean and turns very easily. It was in a old Indiana farm truck owned by a old guy & the truck rusted really bad so he stopped driving it...it was running when pulled. I stopped by harbor freight on the way home & they were having a sell so I loaded up. I got me another 1000 pound engine stand for $39 just for this engine. Im going to break it all down this weekend and see just what I have. Thanks for the info so far guys!

[five7kid]

From everything I've gathered, you've got something better than what you originally said you were getting. 2-bolts are stronger than 4-bolts, because the main bearing webbing isn't weakened by the outside bolts. To really improve strength, get splayed 4-bolt caps installed. Hopefully, the engine got regular maintenance, and not too much farm dust made its way into the carb.

Also, I was under the impression no 400 SBC's came with 4-bbls. But, that may have changed in the later years (but not '74-'75). And, the 3-freezeplug thing only lasted the first couple of years.

Let us know what you find.

[Chris 96 WS6]

I would be very careful what you consider from that head house. You could end up with a set of 882's- not worth the shipping cost, let alone $369.


The '82 truck 350 I rebuilt and put in my '85 Camaro (10 yrs ago) had 882s. I never raced or dyno'd that car though, so I have no clue what kind of power it was putting out...under 200hp probably. But it was lightyears better than the LG4 :D

Man it would be so much fun to build another motor...but time and money are barriers to that project, LOL.

[1970judge]

Man it would be so much fun to build another motor...but time and money are barriers to that project, LOL.

No kidding the last motor i was building was for my firebird. I started on a 402 for it i got to the block,pistons,rods,KS's, and reality set in so i realized i wasnt going to make it because i still needed the ls1 swap stuff. Sure was nice when i had my honda and no bills when i was 16 easier to build motors on no budget.

[Bipolar]

Speaking of farm dust this motor still has the breather on it that says 6.6, yeah, it was a factory 4 barrel..I found out that Summit has there Dart Iron Eagle heads on sale right now. The 215's and 230's are just $450 for the pair bare..

[five7kid]

this motor still has the breather on it that says 6.6, yeah, it was a factory 4 barrel..Seems every rule I think I know has an exception. . .
I found out that Summit has there Dart Iron Eagle heads on sale right now. The 215's and 230's are just $450 for the pair bare..Time to jump!