86 chevy 4x4 400 engine - The 1947 - Present Chevrolet & GMC Truck Message Board Network

knifeman1 · 12-12-2011, 01:38 AM

im looking at an 86 chevy 4x4 truck that claims to have a 400 small block in it .
it has small 400 badges on the front fenders which i know doesnt mean anything . my question is : how do i look at the engine and tell a 400 from a 350 ?

gGMC DOG · 12-12-2011, 02:37 AM

look at the CASTING NUMBERS

http://www.73-87.com/chevy_ids/blockid.htm

BigBlocksRule · 12-12-2011, 07:57 AM

There were only 3 SBC400 casting numbers. They'll end in -817, -509 or -511.
If you can't see the casting numbers, look at the side of the block. A 350 will be relatively flat, where a 400 will have small "bulges" around each cylinder. They're not large, but the side of the block is definitely not flat.

ont_guy_38 · 12-12-2011, 08:26 AM

If it is a 400 the balancer will have a cutout in it like the picture

BigBlocksRule · 12-12-2011, 09:20 AM

^ correct, unless somebody bought an aftermarket with the extra weight on the inside...rare, but it's happened. If you see the offset/cutout, it's either a 400 or a 383.
Good luck, hope it's a 400, they can be beasts!

12-12-2011, 01:38 AM	#1
knifeman1 Registered User Join Date: Dec 2011 Location: Franklin TN Posts: 5	86 chevy 4x4 400 engine im looking at an 86 chevy 4x4 truck that claims to have a 400 small block in it . it has small 400 badges on the front fenders which i know doesnt mean anything . my question is : how do i look at the engine and tell a 400 from a 350 ?

12-12-2011, 02:37 AM	#2
gGMC DOG Registered User Join Date: Dec 2008 Location: Over yonder Posts: 259	Re: 86 chevy 4x4 400 engine look at the CASTING NUMBERS http://www.73-87.com/chevy_ids/blockid.htm

12-12-2011, 07:57 AM	#3
BigBlocksRule Registered User Join Date: Jun 2008 Location: Lubbock, TX Posts: 2,047	Re: 86 chevy 4x4 400 engine There were only 3 SBC400 casting numbers. They'll end in -817, -509 or -511. If you can't see the casting numbers, look at the side of the block. A 350 will be relatively flat, where a 400 will have small "bulges" around each cylinder. They're not large, but the side of the block is definitely not flat.

12-12-2011, 08:26 AM	#4
ont_guy_38 Registered User Join Date: Jul 2007 Location: Ontario Canada Posts: 1,006	Re: 86 chevy 4x4 400 engine If it is a 400 the balancer will have a cutout in it like the picture Attached Images

12-12-2011, 09:20 AM	#5
BigBlocksRule Registered User Join Date: Jun 2008 Location: Lubbock, TX Posts: 2,047	Re: 86 chevy 4x4 400 engine ^ correct, unless somebody bought an aftermarket with the extra weight on the inside...rare, but it's happened. If you see the offset/cutout, it's either a 400 or a 383. Good luck, hope it's a 400, they can be beasts!



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.