I have a 350 small block with a 270 cam and I want to get a bigger one. I am not sure what the guy meant but when I had my engine built he said the 270 cam was as big as I could go with out doing something to my vacuum lines or something with my vacuum components. I was young when this was done so I didn’t know much about engines so I wasn’t paying attention :D . But now I want a bigger one and I just wanted to know if anyone knew what size I should get and if I do go bigger will I have to do anything to the vacuum???? I am looking to get around 500H from the engine. I have Edelbrock e-tech heads not sure what kind of pistons or compression. What should I get????

you need to get a gauge and check how much idle manifold vacuum you have now. Do you have power brakes? A/C? Auto or stick? If auto, do you know the stall speed of the converter? how about the rear gears?

Sorry I dont know the gears it is a auto no clue on the stall speed and no A/C and it does have power brakes. I am sorry I dont know these things but I will get all these things checked and if you want you can subscribe to this thread and I will re-post the answers to it????

Why do you want a bigger cam? It seems your running a pretty stock/mild combo and anything bigger will be too big unless you have something along the lines of a 2500+ stall and 3.73's out back.

268/270 ish is hte cut off for low compression smallblocks. I had a 268 in mine that was perfect, I had intentions of putting a 383 in it and bought the cam and gaskets for it than decided not to go that route after finding I had flattened 6 lobes. I'm putting that cam, Voodoo 276 in mine and know that I'm probably going to loose power from the swap but not enough to bother me, not to mentoin once I do the rear it will make up for it and than some.

What he is saying is that the more cam you run the less vacuum it will make at idle. Less vacuum means that you will have a harder time with your brakes, they will feel like manual brakes almost. That size cam will make a bit of a difference but unless you go really radical you should be fine.