WebJul 9, 2010 · Most stock blocks have this area not drilled. So if you want to improve cooling on a 400 block, or any SBC block for that matter, use the head gasket as a template and drill the holes yourself. The 1/8" steam holes are too small to make any difference. To further improve cooling on a SBC, run water lines from the rear of the manifold to the front. WebMay 27, 2006 · Definitely drill the steam holes if they aren't there already. The exhaust side holes are drilled perpendicular to the head surface, and the intake side holes are drilled at a 30* angle towards the top of the exhaust ports. I use a gasket as a template, a punch to mark the holes, and a dremel and drafting triangle to start the angled holes.
SBC 400 Steamports with Vortec heads NastyZ28.com
WebOct 29, 2024 · Maybe you don't absolutely need to drill the steam holes but I don't see any downside. If I recall correctly, since 400 sbc chevy blocks have siamesed cylinders; the steam holes are supposed to prevent steam pockets (air bubbles) from forming at the tops of the cylinders by providing an escape route. WebFeb 24, 2006 · Discussion Starter · #1 · Feb 21, 2006. I just got my L-98 aluminum heads back from the shop and they didn't drill the steam holes for the 400 block as I had requested. When I asked why, they commented that it really wasn't necessary with the aluminum heads and I won't have any cooling issues. They also commented that the … rifles in 1850
SBC 400 Steam Holes w/L-98 Heads?? - Hot Rod Forum
WebMar 16, 2011 · Steam holes are recommended for all 400 block applications. Use a 400. gasket as a template and drill the three holes nearest the spark plug side of the head … WebJan 7, 2007 · 12,665. I AM ILK. i just recieved my brodix track 1 227's and boy are they purdy. my question is in regards to steam holes for a 400 block. brodix says not to drill … WebApr 25, 2016 · The Ford Racing reproduction Boss 302 block has siamese cylinder walls and can be bored to 4.125". That block has steam holes and Ford recommends drilling matching holes in the heads if they're not already there. I believe the Scrub 400 cu in small block also has siamese cylinder walls. rifles in 280 ai