bbc and tbi help please.

[sweetk30]

i have a 78 454 non emissons lrg oval port 761 heads from 2x4 suburban that was 10k trailer tow package from factory. it has bad cam but ran great till passing gear rpm then poped threw carb some. pulled intake and found flat exaust lobs.
i am going to install in project truck. and am using tbi system on it with 670 holley unit. want to know what cam and lifter , spring combo to use with this project. truck stats are in my profile section. thanks for the help.

 

[ss396]

Based on my experience and you probably already know this, when cam lobes go down a lot of that metal in the oil plays havoc with the bearings. You may want to pull the pan and check out the rods and mains clearances.

When I first got my '67 Chevelle SS, a lobe was worn down, put a new cam in it and the oil pressure was only 10psi at idle. A year, 4,000 miles later, when I had the money to rebuild the engine, the replacement cam was already junk due to low oil pressure. The mains were in terrible shape, the reason for the low oil pressure.

If the the crank looks OK, you can just replace the bearings if they are worn.

Big blocks are cool, sounds like a fun project.

 

[sweetk30]

it had good oil pressure when hot but i will look over the bottom end. and i allready heve a new oil pump to install and 1 piece pan gasket from felpro. thanks.

 

[eagle mark]

When you pick a cam see if they recommend it for TBI.

As a guidline don't go over 214o intake duration @ .050" and 224o exhaust duration @ .050" Problem is TBI uses a Speen/Density system and does not like low vacuum. They can run with bigger but you will need to tune or have someone tune a chip for larger durations and it runs into a lot of time or bucks.

 

[sweetk30]

ttt