FLO-TEC aluminum heads

[Mikej]

I have a SBC I'm collecting parts for. Has anyone bought a set of these:180cc intake runners
Straight or angle plug
62cc exhaust runners
64cc combustion chambers
2.02" and 1.60" stainless steel valves
Hi-Performance springs for .550" lift
Five angle valve job
Bronze guides
3/8" screw-in studs and guide plates
Speedway has them. Price is very reasonable. Wondering if they would ok for a 350- 400 hp engine.

[chimp koose]

Make sure of the quality before you buy.There are some aluminum heads on the market with a low price and even lower quality.My racing partner owns a speed shop and will not sell one brand in particular because the guides and seats are known to fall out . There was an article in popular hot rodding a few years ago where they built a budget 350 with heads from Engine Quest that were cast iron and really affordable. They used a hydraulic cam and made the power you are looking for with a very low budget. If you go to the popular hot rodding site you can find the article  and see for yourself.A quick ballpark number for possible horsepower on a street motor with a particular cyl head is to double the flow rate of the intake port,provided the exhaust port is capable of flowing about  80% of the intake flow.Make sure you are doubling the flow at your cam lift spec , not a number listed past your cams lift.If you are really wanting aluminum heads, Patriot makes a line of inexpensive heads that flow well and are machined in the USA. Also look at the valve spring specs , most of the heads sold with .550 lift springs are running 1.250 dia. springs, these springs typically wear out quickly. If you do not have a set of rebuilt stock heads for your engine I would highly recommend you go with aftermarket heads as they flow so much better than stock ones and can be bought for close to the cost of rebuilding a set of stock heads.