Hey guys I have always wanted to build a 427 because to m understanding they make big block torque, but also rev pretty fast. My questions it there any advantage of a 427 over a 454? Will I be sacraficing a lot of power if I could with a 427 compared to a 454?

Also does anyone have any good 427 combos to but a full weight 56 Belair in the 11's?

thanks
Tom

My 454 never knew it wouldn't rev as fast :D
seriously though if you have a 454 stick with it.

27 has numerous advantges IMHO. It revs like a small block, has great torque, is internally balanced, won't spit the oil pump pickup off the pump, just a nice motor.

I have one in my sons 71, 049 heads, custom pistons from BRC, Qjet and a nasty HYD cam. I reused the TH350 and the 10 bolt, put in a new Eaton posi and new Moser axles from BigGearHead.

won't spit the oil pump pickup off the pump, When does this happen? 5.5 years and 3 years of full time racing and mines still attached :confused: and I'd put the new bullet up against those quick revving 427's, but ya got me on the internal balance deal smile.gif

If you are spitting your oil pump pickup, chances are good that your engine has a balance problem. Engine dyno tests that I have seen show the LS6 making about 25-30 hp more than an L72. I know from personal experience that our L72 would lay a severe beating on our L78. The ports may be overly big for a stock L78, better, for an L72 and great for an LS6. I put in the neighborhood of 200K miles on our COPO Chevelle and the 427 was as reliable as a rock needing only one valve spring and a timing set in that time. 427 or 454 take your pick. They are both great engines and need virtually no attention. That has been my experience.

The (dis)advantage of the 427 is that you have to spin it 500 rpm higher than the 454 to make the same power, and 700 rpm higher to beat 'em! tongue.gif

Therefore, they must be built with the utmost of machining/blueprinting/assembly care. When you're regularly buzzing up to 7200, things have to be correct! graemlins/thumbsup.gif

To me, the question is more - what do you have to work with? If you alreay have a good 427 rotating assembly, I would probably just run it. If you need to get all new parts and do a new build, it's a no brainer - bigger is better.

I made my own 427 from a 402,it had a mild hydraulic cam,black jack headers,and torker intake and a small shot of NOS and it ran 12.30's on motor,11.72 on the gas. This was in my old Camaro with 4.11's. You just don't have to do much to a big block. Either is a good choice,the bigger the better :D

I agree, a 427 small block is a good choice and at least 175 pounds lighter than a rat, with aluminum heads more than 200.

Oh, I forgot this was about rat motors.