Time is getting close

[1980RS]

To running my Vortec 406 again. After having very such good luck last year with this engine I am going to ask some here what they think it might do with only 2 new items, Larger Vortec heads and a bigger camshaft.

Heads, Large port 206cc intake runner heads flowing in the 265cfm Intake and 200cfm Exhaust range
New Cam, .537 I lift and .557 E lift
256°and 264° Duration @.050 on a 105 LCA small base circle

Current cam it .488 I with 1.6 rocker and .510 E with 1.5 rocker
234°and 244°on a 106LCA

The car ran high 10's last year and the test will be, Heads only first then the new heads and larger cam next. What will it pick up at the track or will it slow down?

[steve cowan]

We test stuff very similar ways
I ran a comp oval cam near exactly the same as your small cam yours run real good.
The bigger head is more in line for the cubes in my opinion, are you going to run 1.6 rocker on the bigger cam?
I am going to go back and read some of your old posts to refresh on your full combo save you spelling it out.

[Monza355]

Have you bought the camshaft yet ? Are you sure you need the small base circle for your 400 engine ? I think a small base circle flat tappet cam is a big compromise for reliability.

What converter and stall are you running with the new combo ?

[dannobee]

Have you bought the camshaft yet ? Are you sure you need the small base circle for your 400 engine ? I think a small base circle flat tappet cam is a big compromise for reliability.

True, but it's likely needed for rod clearance. Depending on which rods he's running, they often need the small base cam and you still need to grind on the rods for clearance.

[rustbucket79]

Flat tappet lobes are much less likely to have clearance issues than roller lobes, a regular catalogue cam will work, at worst he’ll need to grind the rods a minor amount.

[1980RS]

We test stuff very similar ways
I ran a comp oval cam near exactly the same as your small cam yours run real good.
The bigger head is more in line for the cubes in my opinion, are you going to run 1.6 rocker on the bigger cam?
I am going to go back and read some of your old posts to refresh on your full combo save you spelling it out.

No with the new cam it will be 1.5 ratio roller rockers.

[1980RS]

Have you bought the camshaft yet ? Are you sure you need the small base circle for your 400 engine ? I think a small base circle flat tappet cam is a big compromise for reliability.

What converter and stall are you running with the new combo ?

I think the bigger cam may be close and I know some of my circle track friends have run this cam without any trouble. The converter will be the same, 8" TCI 5200 stall. Less stall with my 350 engines.