I have a '68 400 motor, and I would like to do a budget rebuild on it for my '67 driver. Since you can't get pistons for these motors, I was wondering if it would be possible to take it out to a stock 430 size, and just use some original 430 pistons out of another block. Are all the 400's able to go to 430, or do they have to be tested? Steve
I have been told that some of the early 400's are "iffie". but that the 68 and 9's are the ones to use for this deal. I too am gonna try and use a 68 400 block and some 430 pistons in a new toy I am putting together. But I won't start that till' after the racecar is done:Brow: Let us know what you find out for sure, I know I would appreciate the info.......... later........................
I hear a lot of "I'm pretty sure" answers on this, but can anyone give me a definite yes? It would be really nice to be able to use the block I have. I'm not going for all out performance anyway- just a somewhat mild steet motor. Thanks for the help.
I did it to my 69 400. Your near me in Ohio. I had it done at Micheal's Autoparts in Macedonia. They sonic tested the block and it was no problem. Good Luck.
I have a '67 and I can't decide whether to buy a 455 or have my 400 punched to 430. It is a numbers matching car and I don't want to take a chance with the block if it is iffy. Are there any tests that can be done before I turn my block into scrap? Steve, I am sorry about tagging this on to your thread but I thought maybe we could both learn a little at the same time. Thanks!
ALL overbores of this nature should most definetely have the block sonic tested! Ask your machineshop, if they don't know what you're talking about, go somewhere else!
The reason why I suggest sonic testing is because there might be core shift in the casting. I strongly urge this in any thin-wall casting bore, or excessive overbores in ANY BLOCK! Just an opinion.
Marlon, Thanks for the info... Michael's is where my dad and I have been taking our motors, so it's nice to hear that they can do this for me. I agree about the sonic testing... it's cheap insurance! mlh48- don't worry about tacking it on. We're after the same info, right? If I were in your shoes, I would find another block to build up, just in case. There are already too many cars out there with the original block gone (ask my dad- '70 stage 1- motor destroyed by original owner!)
400 Pistons Pistons are available for the 400 motor, but you'd have to go to Ross or another "custom" manufacturer to get them. I think you'd pay about a 50% premium over standard forged pistons, probably at least double the cost of stock cast replacements. It might be worth considering if you want to keep the stock motor and don't want to risk a huge overbore.
I think TA has 400 pistons availiable now. You should call and ask. But if you want to do an over bore I would just have it sonic checked(my 69 400 was bored to standard bore 455 without a problem)
When I had mine bored they said it could have gone to 455 with no problem, but I figure I'll use that if I ever rebuild it again.
