360 SBC Build?

[vortecpro]

I have a 360 inch SBC short block I built a while back, I used a Mahle flattop piston with two small valve reliefs, a circle track piston I believe, I worry about piston to valve clearance with a 260 @ .050 cam SFT. I thought about building this with a set of ported 062 Vortec heads and a air gap intake to replace my current 327, heres my questions to this forum:

1. Will those small valve reliefs clear a 260 @ .050 SFT cam possibly?
2. Will the power be considerably better than my 327 with 240 @ .050 SFT cam which makes 446 HP?
3. What RPM will the 360 SBC make peak HP @?
4. I'am looking for a minimum of 6 tenths in the 1320, will it deliver?
5. Should I go right to the 406? It needs to turn over 7000 RPM in the lights.

Thanks

[lefty o]

the answer to every question, is who knows. you dont give enough info to work off of.

[1980RS]

I have a 360 inch SBC short block I built a while back, I used a Mahle flattop piston with two small valve reliefs, a circle track piston I believe, I worry about piston to valve clearance with a 260 @ .050 cam SFT. I thought about building this with a set of ported 062 Vortec heads and a air gap intake to replace my current 327, heres my questions to this forum:

1. Will those small valve reliefs clear a 260 @ .050 SFT cam possibly?
2. Will the power be considerably better than my 327 with 240 @ .050 SFT cam which makes 446 HP?
3. What RPM will the 360 SBC make peak HP @?
4. I'am looking for a minimum of 6 tenths in the 1320, will it deliver?
5. Should I go right to the 406? It needs to turn over 7000 RPM in the lights.

Thanks

Well Mark, my 2nd set of 062 Vortec's picked up my car 5 tenths and 5 mph this year on the 406 with the tiny hyd. cam, I don't think PVC will be a problem on those pistons. I think you know that with the cam on a 106 LCA it will make more power and you have the equipment to make any head sing at the track. So yes, you for sure will pickup 6 tenths with the changes.

[rustbucket79]

If a 406 is an option don’t waste your time with a minor displacement increase, in the end you will be building the 406 anyways.

[F-BIRD'88]

It is going to depend on the cams LSA and installed intake centerline. If 106 lsa in on say 102 deg the VTP clearance will be a bit less than .100" INTAKE (.080" ish) Its the exhaust that counts . Will be fine as long as the cam is advanced like so.. The more cam advance the bigger the critical exhaust side VTP clearance..
Unless the block is 0 decked and heads are shaved too lots of room.

it is up to you to check VTP clearance. The exhaust side is more critical than intake side.

Needs 10:1++ cr.. Needs a 4500++ rpm race converter (8",9") Needs gears to allow 7000++ rpm trap rpm.
Hp peak 6400-6700 rpm.

What exact cam?

Yes the 406 sbc will eat it...

There is a new recent Holley vortec head single plane intake
Shorter than supervic Same height as Vic JR, and perf RPM. Easy under hood fit.
Looks promising.

Yes the 406 will EAT IT.

[vortecpro]

I have a 360 inch SBC short block I built a while back, I used a Mahle flattop piston with two small valve reliefs, a circle track piston I believe, I worry about piston to valve clearance with a 260 @ .050 cam SFT. I thought about building this with a set of ported 062 Vortec heads and a air gap intake to replace my current 327, heres my questions to this forum:

1. Will those small valve reliefs clear a 260 @ .050 SFT cam possibly?
2. Will the power be considerably better than my 327 with 240 @ .050 SFT cam which makes 446 HP?
3. What RPM will the 360 SBC make peak HP @?
4. I'am looking for a minimum of 6 tenths in the 1320, will it deliver?
5. Should I go right to the 406? It needs to turn over 7000 RPM in the lights.

Thanks

Well Mark, my 2nd set of 062 Vortec's picked up my car 5 tenths and 5 mph this year on the 406 with the tiny hyd. cam, I don't think PVC will be a problem on those pistons. I think you know that with the cam on a 106 LCA it will make more power and you have the equipment to make any head sing at the track. So yes, you for sure will pickup 6 tenths with the changes.

Ok thanks, so the bigger cam and more inches at the same compression will be worth 6 tenths?

[vortecpro]

If a 406 is an option don’t waste your time with a minor displacement increase, in the end you will be building the 406 anyways.

Best advice yet...........

[vortecpro]

It is going to depend on the cams LSA and installed intake centerline. If 106 lsa in on say 102 deg the VTP clearance will be a bit less than .100" INTAKE (.080" ish) Its the exhaust that counts . Will be fine as long as the cam is advanced like so.. The more cam advance the bigger the critical exhaust side VTP clearance..
Unless the block is 0 decked and heads are shaved too lots of room.

it is up to you to check VTP clearance. The exhaust side is more critical than intake side.

Needs 10:1++ cr.. Needs a 4500++ rpm race converter (8",9") Needs gears to allow 7000++ rpm trap rpm.
Hp peak 6400-6700 rpm.

What exact cam?

Yes the 406 sbc will eat it...

I think I should take a picture of the pistons and post them so you can see the reliefs, post cam specs then as well.

[F-BIRD'88]

If you already have a usable 400 sbc block and crank there go straight to that.... Watch the 406 compression ratio if Pump gas is required with 64cc vortec heads.
You won't regret the 406 SBC..

[F-BIRD'88]

What ET MPH is the lil 327 running now? car weight.?

[vortecpro]

If you already have a usable 400 sbc block and crank there go straight to that.... Watch the 406 compression ratio if Pump gas is required with 64cc vortec heads.
You won't regret the 406 SBC..

Remember it needs to make peak power @ 6600 and turn 7000 @ the lights, I'am not sure thats possible with a reliable Vortec head? Runs 12.8 @ 105 @ 4100 pounds.

[mt-engines]

It is going to depend on the cams LSA and installed intake centerline. If 106 lsa in on say 102 deg the VTP clearance will be a bit less than .100" INTAKE (.080" ish) Its the exhaust that counts . Will be fine as long as the cam is advanced like so.. The more cam advance the bigger the critical exhaust side VTP clearance..
Unless the block is 0 decked and heads are shaved too lots of room.

it is up to you to check VTP clearance. The exhaust side is more critical than intake side.

Needs 10:1++ cr.. Needs a 4500++ rpm race converter (8",9") Needs gears to allow 7000++ rpm trap rpm.
Hp peak 6400-6700 rpm.

What exact cam?

Yes the 406 sbc will eat it...

There is a new recent Holley vortec head single plane intake
Shorter than supervic Same height as Vic JR, and perf RPM. Easy under hood fit.
Looks promising.

Yes the 406 will EAT IT.

you call a 4500 stall a race converter? thats a good street converter

how do you suppose those heads will make or hold power past 7000rpm on a 406 with an air gap?

id say try the 360 and mock it up for ptv, you might be able to dowel the head for a slight gain in ptv. The duration is in the ballpark for the rpm you want so try it.

[vortecpro]

OK

But how much better is a 360 with a SFT 260 @ .050 and a well ported Vortec head @ 10.5 comp, over a 446 HP 327 that peaks @ 6600 RPM 400TQ?

[F-BIRD'88]

The 406 with vortec heads will make more power but peak out at a lower rpm 6000-6200 . But you can trap rev it as high as you want. to. The valvetrain is the limit.
The 406 will make a mountain of torque.

Cams are cheap if you want to cam it to get "after power"

Gears are cheap too.. 255 cfm on a 2.02 or 2.05" valve full ported yet reliable vortec head is 550 hp capable.

[F-BIRD'88]

Why are you backing yourself into a corner with a "260 deg cam" and a RPM intake if you want to rev it way up?
Seems you are not the 1 making these choices......

I know of off the shelf ft cams that actually will get you there in either the 360 or the 406.