I have a 400sbc and some 062 350 vortec heads that I will be using in a build for my 92 RS. I have decided I'm going with a carb setup, Demon 750cfm carb. I also know I need to get the vortec intake manifold, probably going with a Weiand vortec manifold. I also know I need to get the steam ports drilled on the heads to work properly with the 400 block.

What I'm trying to look up is what is the biggest cam I can go with on these heads?? I don't really care to do extra machine work on the heads for a big *** cam, because I want to drive this car on the road often.

Also I know with stock pistons the CR is going to be around 11:1 which is WAY TO FREAKING HIGH! So I know I need to go with a dished piston but not sure which ones to go with. I would like to keep my CR around 9.5:1 at the VERY most. I say between 9.1:1-9.5:1CR is ideal on this car.

Any ideas, info, specs or whatever you want to give me on different cams, and pistons would be great. I am pretty sure I want to go with a Luminati cam, I hear nothing but great things from them. Thanks in advance!

 

When I checked mine, my retainer-to-seal clearance was 0.485" for the intake. You can get +0.050" locks, but then you need to choose springs to match, and check that the rockers don't hit the retainers, and that the rockers are long-slot if you don't buy roller rockers.

 

http://www.lunatipower.com/Product.aspx?id=1957&gid=280

 

Thanks for all of the help!!!

 

http://www.summitracing.com/parts/CRN-10309-1/
If you want to run a more aggressive cam.

 

For street pump gas compatability and 64cc heads on your 400 you want
a piston with a dish volume between 18cc and 22cc.

If you are going to the bother of building a 400 why not modify the vortec heads for higher lift or get GMPP Bowtie vortecs that are high lift capable out of the box.

These Bowtie heads are way ahead of stock oem 062-906 vortecs.

 

Thanks for the suggestion, but I'm wanting to keep it simple. I'm really just looking to spend the least amount of money on this build. Drop it in the car and go.

 

Since you have the heads off the motor, I HIGHLY recommend you to have the guides cut. It is not expensive. They will already be at the shop. They will already be disassembled. It will take no time and you will never have to worry about it. I would also go ahead and have them put in screw in studs.

You already have to get different springs. Please go ahead and do this. If you dont, you will probably wish you had later. Sometime in the future you might decide to go with a bigger cam to get some more power out of your combo. Guess what, you cant because you tried to save $100 when you put it together.

I went the cheap and easy route because my motor was already installed. It was either do that or pull the heads. The day my heads do come off the motor, I can guarantee to you that they will be sent to a shop for the right work to be done to them.

It is cheap insurance and you will not regret it. Slow down and make sure you do things right. You dont want to have to do it again. Do it right, even if it takes a week or two longer to save up for the better parts.

If you already had the car running, then I would be different. But you will already have the heads at the shop. You should already be having the guides checked, new seals installed, and a valve job. Why not have the guides cut down?

 

I have a 400sbc with vortec heads. Do the heads RIGHT now or you will be sorry later. I went the whole 9 yards with my heads. 202-160 valves, screwin studs, guide plates, cut down guides and ls6 springs. I did a cleanup and opened the ports. I run a cam with 536 lift with room to spare. The compression is 9.8 to 1 runs fine on high test. I converted mine to hyd. roller cam. I run a 780 cfm holly sometimes, I put the dual quads on for a car show. I love the setup. The only problem, if I beat on the car I kill transmissions. The 400 has too much torque for even a built 700r. I now baby my car and have this trans 3 years about 3000 miles. I have been running this setup for over 11 years.

 

If you are not willing to put much in it, don't expect much out of it.

 

Good point everybody, the 305 in the car now runs great. I should not be in a hurry to do all of this.

 

Would it be best to swap out my 700R4 for lets say a T5 or T56? I'm sure a manual will hold up to a torque monster better than an auto will.

 

So I should be looking at:

22cc dish pistons
Cut the guides
Screw in studs (ARP)
Springs (crane)
new valve stem seals
guide plates?????

Am I missing anything?

 

Retainers and locks. The stock retainers go down too far and cut down the valve lift. Match the springs to your cam.I used comp cam retainers and locks. With the guide plates you must use dardened pushrods. The plates will chewup regular push rods. You will have to openup hole where the pushrod goes through the head or the pushrod will not have enough room. With this change you will NO longer have use selfaliening rocker arms, the guide plates keep everything in place.I would go hyd. roller cam. You can get dropin (retofit) lifters for $200 on fleebay. Or do the grind and drill tap way and put in newer style w/spider plate and v6 hyd. roller lifters. I would go the retro way unless you are really heads up doing block grinding and taking apart a lifter to do mods. The retrofit way will only cost you about $80 more. When I did mine a set of retro roller lifters cost $400. The second option only cost me $125. Wait a little longer and do everything while the engine is on the stand. The feeling of dropping in the engine and priming the carb, turning the key and it fires right up can't be beat. You can enjoy your hard work. It cost more to do it later than doing everything up front.

 

what rod length would any of you recommend on a sbc 400 with the vortec heads? And why?

 

I used 350 sbc length w/full foating pins. They are longer and stop some of the stress put on the block with shorter 400 rod. Just have to get the pistons for this setup. The cost is the same as stock pistons.

 

you can get your 700R4 built for racing for half the cost of a t56 install.

T56: $1200 (assuming it's in good shape and doesn't need additional work)
Trans mount: $250
Adapter for speedometer: $350 (depending on what year your car is.. might not need it)
Flywheel: $300
Clutch: $600
Accessories that probably aren't included with the tranny (various): $350

= ~ $3050 as a rough ballpark. Last time I added up my list it was like $3350 or something like that with everything said and done. T56's are great, but they're not a cheap modification to do.. and it's kind of silly to do when you have that 700R4 that would be great for racing with some modification. Put a nice build on it and a good converter and you've got a sweet transmission that you can haul *** with and still get that overdrive in for long trips.


And just a little FYI: I had a T5 Worldclass and sold it... went to a T56, sold that and used the money for a TH350 build because it was cheaper allowing me to put the rest of the money into the engine.