vacuum rule,gauge legal 4412..396sbc

[purestock45]

would a 3.875 crank in a 350 block work for a 15'' vacuum 4412 gauge legal motor?Rules are 350 block,stock oem heads non vortec,any intake,must pull 15'' at 1000rpms....if i can make 13-1 cr will the cam be enough to feed the cubes and still make vacuum?any suggestions?

[DaveBauerSS6]

Never done one of these. Answers should be good reading.

[lilsumo]

would a 3.875 crank in a 350 block work for a 15'' vacuum 4412 gauge legal motor?Rules are 350 block,stock oem heads non vortec,any intake,must pull 15'' at 1000rpms....if i can make 13-1 cr will the cam be enough to feed the cubes and still make vacuum?any suggestions?

Thats a great combo for that set of rules, build as much CR as you can and as many cubes as you can

Isky specializes in cams for these types of engines

[let-r-eat]

I hate these rule sets because compression and cam will be king. Knowing the flow at overlap is the all important key to the city. Overlap is what destroys engine vacuum. What OEM head are you using?

[purestock45]

thinking of the 58cc 305 heads with the 165cc runners or a set of humps

[racer69]

Bought a race ready car to run in a class with similar rules. Everybody claiming they had special cams and tons of "tricks" for making power and vacuum. We ran the car in both oval(me driving) and figure 8 (NOT ME! ) lol. Ran top 3 at least every night with several wins on 8 and flat dominated on oval! Tore that motor down to refresh. Figuring I would find all the "special" stuff like everyone else is running. HAHAHA....the beast turned out to be a Jasper reman performance hunk O junk! cheap flattops....3 different types of stock rods....041 heads bone stock....and a replacement cam! I have put meaner motors in old chevy trucks to drag the trailer with! Moral of the story....just run what ya got handy. Good flowing stock heads and there re some good cams for vacuum rules will put you in decent shape.

[lilsumo]

I hate these rule sets because compression and cam will be king. Knowing the flow at overlap is the all important key to the city. Overlap is what destroys engine vacuum. What OEM head are you using?

I agree these kind of rules suck, all they do is cause you to buy a 250 dollar cam, that is completely unique to the class that you can never sell, and a set of 200 dollar lifters. Then you have to buy a set of 40 year old double hump and sink 500 in them with a competition valve job, angle milling and flat milling. Then they want to run a el'crapo power glide or Saginaw that ends up costing a grand for the complete setup.

I better not get started.