Louisiana Classic Truck Club

Hey all you big block guys.........How was the 1971 402 325hp big blocks?????? Pro's and cons I found one real close to the house and wanted to know how they are is it worth messing with?...... what year would this be ? Gen V 454-4 bolt main......I have always been a small bolck guy and i am building my truck and was looking at power plants for down the road...i am probly going to run my 350 in it for the time being.......just give me somethoughts and some pointers to look for on the 402 if i get to go look at it when i get home.....

Eric

Chevy_Man wrote:Hey all you big block guys.........How was the 1971 402 325hp big blocks?????? Pro's and cons I found one real close to the house and wanted to know how they are is it worth messing with?...... what year would this be ? Gen V 454-4 bolt main......I have always been a small bolck guy and i am building my truck and was looking at power plants for down the road...i am probly going to run my 350 in it for the time being.......just give me somethoughts and some pointers to look for on the 402 if i get to go look at it when i get home.....

Eric

In my opinion, yes it's worth getting, but I collect all the BB stuff that I can, lol. I see the guys on the 67-72 board looking for a 402 every now and then, but if I were to build a BB for myself, I'd go for the cubic inches and build a 454. (more bang for the buck) The old big blocks were hard on push rods, but you can go to a bigger pushrod to fix that. Mike can probably tell you more about it, since he use to race them. I'm not sure what year the GenV came out, but I'm guessing late 90s. It will have the small "peanut" port heads if I'm not mistaken, which, from what I've heard, are good for a DD, or towing, but the hot rodders usually want the 781, or 049 heads, if not the rare rectangular port heads.

Thanks Wynne, i had found the 402 and the 454 in a paper and they are both forsale and they are close to the house and i was wondering on them....shoot they may be even gone already but i would like to know the pros and cons of them so as i am looking i might find something that may a good deal...


Eric

The 402 is what most people call a 396 right? I am with Wynne, if you are going to put a big block in I would go with the 454.

Keith, a 402 is a 396 bored 0.30 over. Not too much there.

Eric, if you want a BB go with the 454.

I'm running a 402 in my truck and I love it. If I had to choose between it and a Gen V 454 i would take the 402 because the Gen V had a lot of problems that GM finally worked out in 96 with the Gen VI block whick is the best one to have. It will work with any head combination through the years. The Gen V will only work PROPERLY with Gen V heads because of leakage in the water passages into the intake valley with the use of GEN IV heads on the block. But I'm gathering for a Gen VI build now and I agree with Kevin if you want a big block THERE'S NO REPLACEMENT FOR DISPLACEMENT!

go with the 454, it will probably have to be bored out to clean up the cylinders, so you will most likly then have a 468(.060), add a decent cam and even with the stock heads, you'll have atleast 400hp. i don't care for the 396 blocks, jmo

GO BIG! lots of torque