Cam knowlege plz.

[mmiddle]

That Lunati cam for a 400 is about right, however, I'm not a turbo guy so others need to chime in here that have knowledge of Turbo-friendly cams.

All little 400's where 2 bolt mains and cast cranks and 2 barrel carbs.

I would be a little hesitant to force induct stock heads and cast pistons with stock rings. Sounds like you are just begging to trash a piston.

[WIDESIDE72]

Originally Posted by mmiddle

That Lunati cam for a 400 is about right, however, I'm not a turbo guy so others need to chime in here that have knowledge of Turbo-friendly cams.

All little 400's where 2 bolt mains and cast cranks and 2 barrel carbs.

I would be a little hesitant to force induct stock heads and cast pistons with stock rings. Sounds like you are just begging to trash a piston.

Not all 400's were 2 bolt main, but that is irrelevent. 2 bolt mains are good for up to 500 with studs.

What was stated above about a cam being too big in a 350 being just right in a 400 is correct.

I had a 383 in a 79 Malibu a few years back with a Comp Xtreme 4x4 X4262H Hydraulic Flat Tappet Cam
Lift: .462''/.480''
Duration: 262°/270°
Lobe Separation Angle: 111°
RPM Range: 1300-5600

It was a BEAST with great torque!


My advice is to call Comp Cams tech line for advice. Be ready with a lot of info such as compression ratio, converter stall, final drive ratio, tire height, etc.

[mmiddle]

WideSide... are you sure on the 4 bolt 400's? I think I remember reading that all 400's where 2 bolts. never intended for performance like Hugger said.

Hugger... Great post. I always get a little fidgety with questions about cam/heads/stall stuff. I've pulled a lot of cams out because someone got starry-eyed and put a big-ol lumpy cam in.

Kawtoom. Think of your engine as an air pump. Heads and intake are critical along with the exhaust. Stock GM heads are crap without a bunch of work. The double humps are goods with work. The rare single humps only need to be cleaned up to be great. Most of the Aluminum heads are good as well with work.

[hugger6933]

As long as we are gonna talk about heads we need to mention the Vortec heads 96-00[+?] small block. Those heads were the best flowing production heads for the small block ever. They even outflowed the first gen bowties and lots of early aftermarket heads in stock form,and warmed over they are even better. Also we cannot forget to talk about the fact that if we are talking 400 we have to talk about steam holes. They have to be placed in the deck of the head or else overheating will ensue. The vortec will produce about 40 hp and 30 ft lbs over a regular production heads, head that it would replace and that has been proven time in and time out by every rag on the shelf, I guess except for Mustang 5.0 and they don't care. oh and while we are discussing the 2vs.4 debate, I belive there were both 4 bolt mains and 4 bbl carbs to be had possibly in the 4x4 truck. Jim