Oil recommendations-SBC 383

[sru1436]

Hello everyone-

Maybe I’m overthinking this, but here it goes:

Looking for oil recommendations for a fresh 383 SBC in a street-driven 1972 C10.

Build Specs

• 383 SBC (4.030” x 3.750”)
• 9.54:1 compression
• Scat cast steel crank
• Scat 6.0” rods w/ ARP bolts
• Wiseco Pro-Tru forged pistons (7cc dish)
• AFR 1038 heads (195cc intake runners, 75cc chambers)
• Summit 1222 hydraulic roller cam
• 218/227 @ .050
• .525/.520 lift
• 110 LSA, installed at 109 ICL
• Morel hydraulic roller lifters
• Melling M55HV high-volume oil pump
• Clevite MS909P mains
• Clevite CB663P rods
• Main bearing clearances: 0.0028”–0.0031”
• Rod bearing clearances: 0.0030”–0.0032”
• Wiseco moly rings, 0.018” top / 0.020” second

Dyno Results

• 412 hp @ 5,800 rpm
• 431 lb-ft @ 5,000 rpm
• Maxima 10W-30 break-in oil on dyno
• Oil pressure was approximately 72–76 psi during pulls

The builder recommends changing the oil after the first 50 miles and then running conventional oil for the first 1,000–2,000 miles. Based on the bearing clearances, he recommends either 10W-30 or 10W-40.


My plan is to run Valvoline VR1 Conventional 10W-30 for the first 1,000–2,000 miles, then switch to a long-term oil.


The truck is a street-driven cruiser, not raced or tracked, and lives in California’s mild climate. Looking for thoughts on oil viscosity and long-term oil recommendations after break-in.

Thanks, Matt

 

[Speedbird001]

Sounds well planned. Curious why Summit branded cam?

I'm guessing this will be low mileage per year? I'd do top shelf 10-30 with annual changes if it was me (ie HPL or the A[cult] )

 

[fantastic]

I'd lean more towards the 40 grade. Start with 5w-30 or 10w-30 for the few thousand miles & then a 5w-40 all year oil. If you live in a warm climate then a 10w-40 if it saves you money.

 

[burbguy82]

My plan is to run Valvoline VR1 Conventional 10W-30 for the first 1,000–2,000 miles, then switch to a long-term oil.

10w30 VR1 would be my choice in this application for forever. It is widely available, reasonable priced, and conventional.


For boutique, 10w40 HPS Royal Purple or High Zinc 10w40 Amsoil

 

[kschachn]

I’d use a euro 0W-40 which comes with sufficient ZDDP and HT/HS, and achieves stringent manufacturer approvals such as Porsche A40. Oil grade recommendations based on bearing clearances represent a minimum, not a maximum. And the winter rating is irrelevant for that.

 

[JeffKeryk]

With a roller cam, Zinc is not an issue. I'd run a nice 5w30 or 10w30 Mobil 1. That's what was recommended by Chevrolet in my C4 Vettes.

 

[addyguy]

Synthetic 10W-30 HDEO is what I’d run in it.

 

[skyactiv]

The rod and main bearing clearances appear on the upper limit. You want a >3.5 HTHS oil in that engine and a 0W40 or 5W40 Porsche A40 spec oil is a good choice. Don't get talked into a HDEO oil.

 

[sru1436]

Sounds well planned. Curious why Summit branded cam?

I'm guessing this will be low mileage per year? I'd do top shelf 10-30 with annual changes if it was me (ie HPL or the A[cult] )

That’s the cam the engine builder picked. I told him strong motor with good vacuum. It made 413 horsepower and 430 torque. I’m happy with it.

 

[UncleDave]

Looks nice.
Have a copy of the dyno run?
I'm curious to look at the low side of the curve.
Thanks Matt.

If it were mine I'd run what I ran my 500/500 406 on - Mobil 1 0w40. Preferably the euro formulation.

 

[sru1436]

Thanks for the recommendations thus far. The truck will be drive maybe 1000 miles a year, if I’m lucky, I also have a chevelle I try and drive. Not to mention a 2001 Chevy truck. I only live 6 miles from work so it’s hard to rack up a lot of miles in my POV.

 

[sru1436]

Looks nice.
Have a copy of the dyno run?
I'm curious to look at the low side of the curve.
Thanks Matt.

If it were mine I'd run what I ran my 500/500 406 on - Mobil 1 0w40. Preferably the euro formulation.

 

[Chris142]

You simply do not need that kind of oil pressure. I would try a 5w30 first.

 

[burbguy82]

10w30 VR1 would be my choice in this application for forever. It is widely available, reasonable priced, and conventional.


For boutique, 10w40 HPS Royal Purple or High Zinc 10w40 Amsoil

I forgot Delvac 1300 10w30 to the above.

 

[chainblu]

I would run your favorite 5w or 10w30.

 

[PontiacHO]

Hello everyone-

Maybe I’m overthinking this, but here it goes:

Looking for oil recommendations for a fresh 383 SBC in a street-driven 1972 C10.

Build Specs

• 383 SBC (4.030” x 3.750”)
• 9.54:1 compression
• Scat cast steel crank
• Scat 6.0” rods w/ ARP bolts
• Wiseco Pro-Tru forged pistons (7cc dish)
• AFR 1038 heads (195cc intake runners, 75cc chambers)
• Summit 1222 hydraulic roller cam
• 218/227 @ .050
• .525/.520 lift
• 110 LSA, installed at 109 ICL
• Morel hydraulic roller lifters
• Melling M55HV high-volume oil pump
• Clevite MS909P mains
• Clevite CB663P rods
• Main bearing clearances: 0.0028”–0.0031”
• Rod bearing clearances: 0.0030”–0.0032”
• Wiseco moly rings, 0.018” top / 0.020” second

Dyno Results

• 412 hp @ 5,800 rpm
• 431 lb-ft @ 5,000 rpm
• Maxima 10W-30 break-in oil on dyno
• Oil pressure was approximately 72–76 psi during pulls

The builder recommends changing the oil after the first 50 miles and then running conventional oil for the first 1,000–2,000 miles. Based on the bearing clearances, he recommends either 10W-30 or 10W-40.


My plan is to run Valvoline VR1 Conventional 10W-30 for the first 1,000–2,000 miles, then switch to a long-term oil.


The truck is a street-driven cruiser, not raced or tracked, and lives in California’s mild climate. Looking for thoughts on oil viscosity and long-term oil recommendations after break-in.

Thanks, Matt

Many good recommendations for oil. Tell us about intake, carburetor, distributor, and current initial timing and curve. That must be a very conservative dyno.

 

[PontiacHO]

Sounds well planned. Curious why Summit branded cam?

I'm guessing this will be low mileage per year? I'd do top shelf 10-30 with annual changes if it was me (ie HPL or the A[cult] )

Summit cams were repackaged Crane cams for years. Now there’s only one cam foundry in the US. That’s at least as of 2025. May be shut down now.

 

[stanlee]

40wt ACEA A3/B4 oil of your preference

 

[sru1436]

Many good recommendations for oil. Tell us about intake, carburetor, distributor, and current initial timing and curve. That must be a very conservative dyno.

Intake is a weiand stealth (long discontinued version) MSD HEI, total timing is 38 degrees at 3800rpm. I just picked up the engine yesterday from the builder, I still have to put in it the truck. I have to see what initial is set at and mechanical in the distributor, haven’t looked at the paperwork for the distributor yet.

 

[sru1436]

Summit cams were repackaged Crane cams for years. Now there’s only one cam foundry in the US. That’s at least as of 2025. May be shut down now.

Here is the cam card, the build sheet for the engine I believe says it’s a billet core.