goin with stock 997 heads on 400 sbc

[4thgentruck]

To save as much as i could im gonna run the stock 997 heads. After tearing motor apart i found the guy had a broke spring resulting in the compression loss in the cylindar. I found a local shot that will true the heads and replace the valve seats for 140. So my plans are this for my 406.

400 sb bored .030 over
997 heads 76cc, with stiffer springs and roller tip rockers
Crane cam hmv-278-2 and lifters
Stock 400 crank(will have turned)
5.7 rods
Dished .030 pistons
Edelbrock performer intake
454 tbi

Hope to have a decent play toy when completed.

 

[Green79Scottsdale]

Couple observations.

Seeing as how you are sending your heads off the a shop, did you ask about going to bigger valves? Just asking.

Make sure you do the math on them pistons. These 400 had terrible compression from the factory, like 7.5:1. Advertised is higher than what the actual measured is on most of these. You may not be wanting to dished pistons with those big combustion chambers.

Getting the blocked decked? Align hone the crank journals? Not necessary but not bad ideas. I see you are doing it "budget" so I assume not.

Looks like a good solid build!

 

[HotRodPC]

Are you sure that cam calls for stiffer springs? Keep in mind stiffer springs means quicker cam and lifter wear. Even though roller tipped, still hydro lifters right?

You sure you''re running a 5.7 Con Rod??? OE SBC 400's generally DO NOT run a 5.7 rod. The ONLY small block that does not. The OE SBC 400 rods are shorter to make up for the longer stroke. But, IIRC, there are some aftermarket SBC 400 Rods that are 5.7, but they're not cheap, and you must have the pistons with the correct compression height to go along with then too. But, I'll swear nothing on the SBC 400. I'm rusty on that info, #1, and #2 it's been so long since I dealt with one, I know there is more aftermarket options. Just saying, make sure you're doing all your math and it adds up correctly. I'd hate to see you spend the funds and then it not work out.

You know you can actually use any SBC heads on the SBC400, just you will have to have the machine ship drill the steam holes in the heads. G79S brings up a good point about the compression. Even if you found some 72cc or 69cc heads would be better, or use the same heads if you like them and smaller dish volume as also suggested in the piston.

Do you mind saying what kind of cash you're throwing at this build? Just wanted to suggest look over your options very good. The SBC400 has been known to have some reliabilty issues. To give up 17 cubes, it might be better to do a 383 build to gain block reliability in a 350 block.

For those who aren't aware, a 383 stroker motor is actually a SBC 400 Crank turned down so the journals fit in the 350 block. That's how it was done back in my street racing days.
Now days there are 383 rotating kits that are designed, engineered and made specifically to be 383 Stroker Kits.

If you're getting by cheap with what you got, go for it. Just be sure to get the SBC, hot tanked and magnafluxed at the machine shop.

 

[4thgentruck]

Good point on the pistons guys. Ive been tossing around the whole thing first.people tell me to go dish then flat top. Alot of unaware builders out there. Im trying to get out as cheap as possible im unemployed and collecting disability from the military. Id love to run vortec heads but like i was saying as cheap as i can.

Ive read where u can use the 5.7 rods but the pin is higher in the piston so it works out. I really dont want to do 383 cause ive bought this motor and id have to go out and find a 350 now.

And i planned on getting the heads trued as well as the block.

 

[Green79Scottsdale]

He is going to a 5.7 rod. You are correct that you need the correct compression height, but you also go through all this when you do a 383. The pistons that come in the 383 kits usually have the wrist pin moved up, which corrects the compression height issue. So you are doing it either way. And you can also use any stock 5.7 rod. The prefered stock rod is the "pink" rod, LT1 rods I believe.

I see the pistons as being the most non-budget friendly out of everything. Compression height, wrist pin location, overall compression, head volume, and deck height all need to be taken into consideration when it comes to pistons. I would guess it may not be an off-the-shelf piston either. You would be best served to call a piston company and talk to them about your plan and see what can be done for you.

 

[Green79Scottsdale]

I would suggest finalizing your plans before buying anything or/and having anything machined. While they are truing up the deck they might as well tailor it to all your components. The more blueprinting you do in the beginning the easier everything will come together and the better build quality you will get. I know your on a budget, but doing things right now can avoid headaches down the road and having to re-do your work, which then moves you out of the budget category.

 

[4thgentruck]

Yea thats true what ill do is call around ive been researching what to do to get the best hp/torque and also get the best fuel economy i can.