Fb with v6 build
Joined: May 2004
Posts: 129
Likes: 8
From: washington
naw didn't catch it lol a few people have said not to use the 4.3 but I thought it was a good fit what did you do to your motor
they're not exactly rev happy engines in stock form.
Joined: May 2004
Posts: 129
Likes: 8
From: washington
In 1996 GM came out with the L31 vortec 5.7(350) it was the last of the gen 1 SBC. They changed the intake and exhaust ports to an improved LT4 style. Guide to retainer clearance is and issue when using a higher lift cam. The change carried over to the 4.3 in the same year. The L31 vortec heads have been know to support 425+ Hp.. so x 2/3 is what the 4.3 is capable of.
In 1996 GM came out with the L31 vortec 5.7(350) it was the last of the gen 1 SBC. They changed the intake and exhaust ports to an improved LT4 style. Guide to retainer clearance is and issue when using a higher lift cam. The change carried over to the 4.3 in the same year. The L31 vortec heads have been know to support 425+ Hp.. so x 2/3 is what the 4.3 is capable of.
just a few mods and it fits like a glove and only problem I have with this motor is the clearance with the good I have to cut and make vents so it will shut
In 1996 GM came out with the L31 vortec 5.7(350) it was the last of the gen 1 SBC. They changed the intake and exhaust ports to an improved LT4 style. Guide to retainer clearance is and issue when using a higher lift cam. The change carried over to the 4.3 in the same year. The L31 vortec heads have been know to support 425+ Hp.. so x 2/3 is what the 4.3 is capable of.
Joined: May 2004
Posts: 129
Likes: 8
From: washington
don't starve it of oil or it will spit the rods out.. don't spin it over 6500rpm (Mine fuel cuts at 6400)
I run a 10% Melling performance select pump stock pressure.
Pick up is ~5/16" off the bottom of the pan.
ARP rod and main bolts.
Balanced to a 50% bob weight (need lighter then stock pistons to achieve this)
3/4 grove mains helps get a little more oil to the rods.
.0025 (up to .003 is fine)main clearance.
.0025 rod clearance.
10w30 in what ever brand..
You can also fill the block to the bottom of the front freeze plugs. I also never go over a .030 over bore on anything.
Find a 3.636 R&P out of a 80s rwd 626 5spd..
I run a 10% Melling performance select pump stock pressure.
Pick up is ~5/16" off the bottom of the pan.
ARP rod and main bolts.
Balanced to a 50% bob weight (need lighter then stock pistons to achieve this)
3/4 grove mains helps get a little more oil to the rods.
.0025 (up to .003 is fine)main clearance.
.0025 rod clearance.
10w30 in what ever brand..
You can also fill the block to the bottom of the front freeze plugs. I also never go over a .030 over bore on anything.
Find a 3.636 R&P out of a 80s rwd 626 5spd..
Joined: May 2004
Posts: 129
Likes: 8
From: washington
One other thing, set your pinion angle at ride height to match the output angle. Make sure the working angles of the u-joints is between 1-3° (closer to 1° if your really going to spin up the drive shaft)
don't starve it of oil or it will spit the rods out.. don't spin it over 6500rpm (Mine fuel cuts at 6400) I run a 10% Melling performance select pump stock pressure. Pick up is ~5/16" off the bottom of the pan. ARP rod and main bolts. Balanced to a 50% bob weight (need lighter then stock pistons to achieve this) 3/4 grove mains helps get a little more oil to the rods. .0025 (up to .003 is fine)main clearance. .0025 rod clearance. 10w30 in what ever brand.. You can also fill the block to the bottom of the front freeze plugs. I also never go over a .030 over bore on anything. Find a 3.636 R&P out of a 80s rwd 626 5spd..


