Thread: out with old....in with the 400...

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ok so i just had sold my 355....made right around 300 whp....lookin for more power....i have a 509 casting 400....and goin with Scat rotating assembly....steel crank forged 5.7 i beams and forged SRP pistons.(9.8.1 compression)..also pry a eldebrock mech 800...and rpm air gap mainfoid...but i need help with the heads and the cam....so i was lookin at the motown 220's.....any good, bads...to em...and damn good price too....i think there good for the 406 displacement seem to flow good at mid lift too ....or the afr 210 elims..and next is the cam....i do belive i wanna go soild...always been hyd...and will have up to a 150 shot on it....do i really need a nitrous cam for a smaller shot...?...or is there a cam anyone can suggest that they have a had good results with....btw....its a 1980 vette 4:10's TH350 and 3500 stall....it wouldnt be sprayed constantly just here and there....thanks for any input...

I would find me a 817 casting first of all. Then I would go with 6 inch rods if within your budget. As for cam and heads, I am not the one to comment on that. Too many variables.

Not to hijack this thread, but I have an 817 casting 400. What is the difference? Saving mine for a future project.

Originally Posted by Biff

Not to hijack this thread, but I have an 817 casting 400. What is the difference? Saving mine for a future project.

The 817 block had a higher nickel content and weights 10-20 lbs more, I forget now. Everyone always speaks of the 509 and the 511, but I wouldn't use either one of those.

Thanks, Typhoon! Now maybe someone will chime in on heads and I can pick up some good info on that, too. I have the 1.94 76cc heads, worked pretty good on my boat, may need to make some changes for a street motor with a manual trans.

the 509 casting has high nickel content. i have 2.

Originally Posted by tim_bo16

the 509 casting has high nickel content. i have 2.

Hey Tim, I once weighed the two blocks in question and I found the 817 to be 10-20 lbs heavier, I would recheck it if I were you. My machinist also verified that the 817 block was harder to machine.

Be that as it may, the new Dart block is the way to go for big power if you can afford it.

200 and 210's are generally way too much head for street use....Unless you're going to wind the snot out of it....Something in the 180 range might be more suited to street use....

For the cam, think I might be looking at the hydraulic roller's. Lots of good selection and some very good street performance!!!

Too much cam and too much head can turn a stroker into a real pooch.....

Originally Posted by TyphoonZR

Hey Tim, I once weighed the two blocks in question and I found the 817 to be 10-20 lbs heavier, I would recheck it if I were you. My machinist also verified that the 817 block was harder to machine.

Be that as it may, the new Dart block is the way to go for big power if you can afford it.

No need to recheck....The 509 block is on average 11-13 pounds lighter than it's counterparts. Why? because it does have 13-15% more nickel in the casting. Therefore it was lightened by GM for what ever reasons the myths out there state. Then again, you don't want the 509's? Ship them to me! By the way, in the two years (86-87) I had the pleasure to work with Bill mitchell, he was the one that pointed it out to me. I've never had any failures with that block (two bolt 509) but a few with 511 and 817. Lucky? Maybe, but I'll take it.