Thread: Need a new donk

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G'day, Im new to your forum and enjoy the info greatly. I would like advice on a new big block for my 57 Chev. I have just removed the old LS7 and ready to start on something big and scary. It dose need to run on 98 octane and go out crusing. Im thinking around 540/ 572, maybe blown. I'll get a local guy to build it. What block is best? Dart or World. Tall deck or stick with standard. What stroke and bore would you guys run for good torque. I have older Big Brodey aluminium heads so I'll probably run them. Primarys are 2.25" and 4" collectors. Id like to be in the 700 hp club. What do you think.
Drive line is T400 with 4000 stall. 9" 35 spline with 4.56 and 29" tyres.
Its raining in Sydney town tonight.

I'll let some of our engine building experts help you on your motor, but just wanted to say welcome to the forum.

Don

just wait a lil while and i'm sure Pat and Erik will jump on this one.... they'll probably tell you every part you need down to which brand assembly grease to use .... but welcome to the forum....

Welcome to CHR ! I too will defer to our engine building wizards, but if you're totally thru with the old LS7 I will send you my address and you can crate it up an send it to me. I'm sure I can find a nice retirement home for it.

Originally Posted by Flatblack 57

G'day, Im new to your forum and enjoy the info greatly. I would like advice on a new big block for my 57 Chev. I have just removed the old LS7 and ready to start on something big and scary. It dose need to run on 98 octane and go out crusing. Im thinking around 540/ 572, maybe blown. I'll get a local guy to build it. What block is best? Dart or World. Tall deck or stick with standard. What stroke and bore would you guys run for good torque. I have older Big Brodey aluminium heads so I'll probably run them. Primarys are 2.25" and 4" collectors. Id like to be in the 700 hp club. What do you think.
Drive line is T400 with 4000 stall. 9" 35 spline with 4.56 and 29" tyres.
Its raining in Sydney town tonight.

I would build a 540/565 low deck engine.
I would run the Dart block.
What is the port volume on your heads?
For the bigger engine I would run a mech. roller cam.
I would look at something in the 270 to 275 area at .050. the reason being is you would need to run a looser stall to run much more cam.
At 98 octane you could run 11 to 1 for a comp. ratio with out a problem.
I would also try and run a cam that does not require you to run a bronze dist. gear.
Have it cut on 112 L/S if you want to run N2o.

Thank you for the welcome. Eric, why a short deck. How many rebores left if you start at 540. What stroke and rod length. The heads are 110 cc and flow about 670 hp. I had a roller in my ls7 but the lifters jammed. I was told dont run rollers on the street, they dont like to idle. What is the prob with a bronze dist gear. Will a 671 get me to the 700's. I just noticed you have what I want. Tell me about your Chev.