Hello Fellow Indian Chiefs!Would like to ask some of you for some tribal knowledge around a 428 engine.I am hearing lots of stories about how this particular engine and set of heads I have can run really good or really bad. Currently mine is running very poor. With that said here is what I have and is it worth putting money into or should I swap for a 400 or 455? 1967 428, 360 hp application with 62 Heads.Only making about 155 to 160 psi on compression.Currently block is going to be tore apart and looked at due to metal shaving found in the oil this past spring. This motor is in a 68 Gto Conv. Body.I am not the original builder of the motor.If I need to post more information I can.Thanks
hello;welcome to the site.if it is steel in the oil it is likely bad cam.how did your eng run before?what did you want to change reg perf ie., more rpm or more tq etc.?do you want a mild, moderate or nasty idle?drag car, fwy flier or inbetween?tire roaster or tire warmer?how much money do you have?what is your current cam?has your block been 0 decked?imo, 160 compression is close to the max you want in a 428 using 93 octane. i think chris has 165.a 455 will make more power than a 428 but a 428 can make plenty.chris austria has a fairly fast 428 that just spins the tires off the line in his 66 gto but a lot of that is due to the light rear end on those cars.here is his car running. it has a mild lope and sounds kind of mild. do you want yours to be more obnoxious, lol?https://www.youtube.com/watch?v=WOTjcHib_0Y here is his drag race. he had to leave slowly to minimize tire spin. these numbers are not fast but once he gets traction and practice he should drop around .5 seconds. 1/8th mile = 9.2estimated 1/4 mile = 14.3http://www.youtube.com/watch?v=dAg-1tBZ0IY
It really don't make any difference, but all the head charts I looked at, show the '67 428 to have 670 heads. And the 16's and 62's came along in '68-'69. But the 62's could have been installed at the very end of the '67 model year I suppose. Or somebody could have added 'em later.Anyhow, the 428's show to have about 10:1 CR even with dish pistons. That's more than most engine builders recommend for iron head pump gas engines.I'd try to sell the 428, since it should be worth a fair amount, with the 62 heads on it. If you just wanna cruise, a good pump gas 400 will work. But if you want some low end torque, then a 455 or a 400 stroker pump gas motor might fill the bill better.You can buy a crate motor and have it shipped to you. Or you can try to round up the parts and have your local Pontiac engine guy(if you have one)build it for you.Here's just a guide to what's available, and their prices.385hp pump gas 400:http://lenwilliamsautomachine.com/400_Long_Block.htmlHere's a 425hp 455 pump gas motor with eagle crank and rods for $4500:http://lenwilliamsautomachine.com/455_Long_Block.htmlAnd here's a 4.25 stroke 400 block short block, which you can buy, then add your cam and heads, or have these guys to put it together with some 6x heads as a pump gas crate motor.http://lenwilliamsautomachine.com/455_Short_Block.htmlThe main ingredients I'd want are low end torque, forged rods and pistons, a CR somewhere between 9.0 and 9.5, and a GOOD Q-jet. Hey, alum heads and intake would be nice if you wanna spend that much. But you can have a nice motor without either.
Jason,Welcome to the forum.. I wouldn't be afraid to hang on to that 428 at all. Those heads on a 428 (68-69) were used in several applications from 340HP to 370HP motors. Biggest difference being the camshaft selection and CR. I believe the 370HP version had 10.5:1 CR.You can set up a 428 for either gobs of low end torque or high end HP depending on your needs/wants. The R/S and B/S Ratios are very close to optimal allowing either direction, especially if you bore the block some. The 428's typically had a strengthening rib running front to back cast into the block on one side, where the oil pan bolts up. That and the use of 4 bolt mains make this a VERY strong block.The setback is anything over 9.5:1 CR is too much for Pontiac iron heads on todays gasoline, unless you have access to 98+ octane.How many miles on the motor since it was last looked at?If you decide to go ahead and sell the 428, send me a PM.. I'm running a 428 and could use a standby block..