Used LT1 350 Camshaft Swap Into Truck Block w/Vortec Heads?

[L31MaxExpress]

It is spring pressure that is the issue. I found valve float show up at 4,500 in the L31 in my Express once. Upgraded to the LS6 springs on Comp 787 retainers and I could rev cleanly to 6,000 rpm after without the dyno chart looking like a 7.0 earthquake at high rpm. The difference was over 28 rwhp at 5,200 and climbed past 40 rwhp at 5,500. Engine was pulled to the stock 5,600 rpm fuel shut-off at the time. The OE springs had such bad harmonics it lost 30 rwhp between 5,150 and 5,350 rpm. The stock springs are only like 70# on the seat new and mine were down to 55# when tested.

 

[98 Nitro]

Why not just sell the engine to a Camaro/Firebird owner, and install something like the Sum 8800 cam?

 

[L31MaxExpress]

Why not just sell the engine to a Camaro/Firebird owner, and install something like the Sum 8800 cam?

Not a bad approach either. I have had both a LT1 and production LT4 cam in L31s and they do make good power. I also pulled the TPI off a L98 350 in a F-car once, put a vortec low rise performer dual plane, 650 Holley 4bbl and HEI on it, headers, decent 3" single exhaust exhaust using a magnaflow crossflow muffler and stock vortecs. It ran low 13s with the stock L98 cam and 1.6 rockers. Car drove like stock until the go pedal was floored. When that 350 expired, the car got a low mileage ZZ3 crate engine swapped into it. The ZZ3 pushed it to 12.70s. The ZZ3/4/5/6 cam has strong power throughout most of the RPM range in a 350 and it is easy on the valve train.

 

[tayto]

Not a bad approach either. I have had both a LT1 and production LT4 cam in L31s and they do make good power. I also pulled the TPI off a L98 350 in a F-car once, put a vortec low rise performer dual plane, 650 Holley 4bbl and HEI on it, headers, decent 3" single exhaust exhaust using a magnaflow crossflow muffler and stock vortecs. It ran low 13s with the stock L98 cam and 1.6 rockers. Car drove like stock until the go pedal was floored. When that 350 expired, the car got a low mileage ZZ3 crate engine swapped into it. The ZZ3 pushed it to 12.70s. The ZZ3/4/5/6 cam has strong power throughout most of the RPM range in a 350 and it is easy on the valve train.

You are talking about the F-body LT1 cam, not the B-body cam correct?

 

[L31MaxExpress]

Not a bad approach either. I have had both a LT1 and production LT4 cam in L31s and they do make good power. I also pulled the TPI off a L98 350 in a F-car once, put a vortec low rise performer dual plane, 650 Holley 4bbl and HEI on it, headers, decent 3" single exhaust exhaust using a magnaflow crossflow muffled and stock vortecs. It ran low 13s with the stock L98 cam and 1.6 rockers.

You are talking about the F-body LT1 cam, not the B-body cam correct?

Correct, B-body cam is practically the same grind as a L30/L31.

 

[Majoraslayer]

Why not just sell the engine to a Camaro/Firebird owner, and install something like the Sum 8800 cam?

That's a great plan, provided a Camaro/Firebird owner was anywhere near me looking to buy one lol. As it is, I'll probably be buried with this thing to get it out of someone's way some day.

 

[tayto]

Correct, B-body cam is practically the same grind as a L30/L31.

right. i seem to remember guys using that cam in 305s on TGO for budget builds.

 

[L31MaxExpress]

right. i seem to remember guys using that cam in 305s on TGO for budget builds.

I always said get something bigger myself. I personally hate the stock B-car or Vortec cams.

 

[tayto]

I always said get something bigger myself. I personally hate the stock B-car or Vortec cams.

i always liked the L98/9C1 cam, seems very similar to the Lt1 f-body cam

 

[L31MaxExpress]

i always liked the L98/9C1 cam, seems very similar to the Lt1 f-body cam

I always liked the LT4 cam paired with 1.6 rockers, especially when they could be had fairly cheap from GM. I built more than one engine with the then inexpensive LT4 rockers and net lash studs. I loved being able to just torque the rocker nuts on and go. Also ran a lot of ZZ3/ZZ4 cams. That 208/221 @ 0.050, 112 LSA, 0.474/0.510 lift has a very flat torque curve with Vortec heads, has good idle vacuum and sounds good at idle.