Im gettin a good deal on a pair of fastburns but if that does not work Ill go with vortecs. Anyway which 350 block will work with these heads? My l98 is getting tired and I want a block that can support 380-425 hp.

 

I'd suggest a Chevrolet one.

Your existing one, or one just like it, would work fine.

 

Any small chevy block will work.... An '87-up roller block would be the prefered block though...

 

I was also wondering- will all headers that fit the stock heads fit the vortec heads as well?

 

Yep, all production heads are the same, your headers will bolt up just fine, aftermarket heads are a different story though...

 

I am building a .040 over 400 with FastBurns.

I have SLP 1-3/4" headers and they DO NOT PROPERLY FIT the d-port shape in the heads. I have bolted the headers to the heads without valves in the heads (on the workbench) and checked the fit.

The header flange physically bolts to the FastBurn head but the ports of the headers overlap into the opening in the heads.

In other words, the 1-3/4" SLPs are smaller than the exhaust openings in the heads. AND the exhaust port of the head rises a great deal higher than the upper opening on the header (the 'd' of the d-port).

I have considered "porting" my headers but have concluded the remaining flange material would be too thin to prevent warpage and/or leakage.

I am looking into other header options including having a "true" d-port header flange installed on a set of 1-3/4" (or larger) headers.

This is my experience with FastBurns. I cannot speak for cast-iron Vortecs.

jms