[claypoolxx]

i recently found out that my pontiac 400 needs a rebuild and the guy at the machine shop has a chevy 400 that is done up nicer than i can afford to do the pontiac, but for around the same price. my question is, what would i need to change in order to th chevy to go in. will i need new engine mounts? alternator brackets? or basically anything thats really going to run up the cost.

[claypoolxx]

i recently found out that my pontiac 400 needs a rebuild and the guy at the machine shop has a chevy 400 that is done up nicer than i can afford to do the pontiac, but for around the same price. my question is, what would i need to change in order to th chevy to go in. will i need new engine mounts? alternator brackets? or basically anything thats really going to run up the cost.

[claypoolxx]

oh i forgot, its going into a 65 le mans, 4 spd, convertible.

[Txbobcat]

#1 on the list is You will DEVALUE the price of the car tremendously. Pontiac people will look down on you. Chevy people will not look up to you. I doubt if your wife and kids would like you any more. All for the sake of saving a few bucks?

[Txbobcat]

My first answer may have been a bit sarcastic so I will answer your real question. First if automatic you need a new transmission if standard new bell housing clutch flywheel etc. New mounts alternator brackets and Chevy could be mounted opposite where the Pontiac alt is sitting now also ps pump could cause problems as well. New radiator is possible or might have to use those extra long generic hoses in case the necks on the radiator are opposite, New exhaust and manifolds. I believe your cost and LABOR will be extremely higher than dropping in the rebuilt Pontiac motor and no matter how good you are it will be considered a botched job. Once again you will DEVALUE the GTO tremendously. I mean thousands of Dollars of value will be lost. Chevy parts cost less than Pontiac parts only because there are more of them out there. Your machine shop is trying to sell you something he already has money sunk into. He is not doinmg you any favors. He knows what you will be up against. I would look around for a new machine shop. Call around and get many prices before making any decision.

[mike nixon]

i'll assume this 400 is a small block.

another thing to consider is the 400 sbc is externally balanced, this makes finding a manual trans flywheel kind of tough. oem units are almost nonexistant and aftermarkets were pricey the last i had checked.

the 400 is the only sbc that is externally balanced.if the assembly hasn't been balanced be sure to use a good aftermarket vibration dampener.

if it's a 4-bolt main block be sure to have it magnafluxed before you put any money in it. they have a tendency to crack thru the rear main bearing surface.

the engine stands for the chevy are going to be different than the pontiac. you'll want to make sure the 400 has provisions for the early style mountsthat the 65 used.

if the engine doesn't have the oem heads with it be sure the ones that are used have had the steam holes drilled correctly or you'll have heating issues.the 400 has siamesed cylinders.

you'll also want to change the front springs in the car due to the weight difference in the engines.


i'd build the pontiac that was in your car. in the long run it will be a better value for the money spent.

mike

[claypoolxx]

thanks guys,

i just remembered that the guy at the shop had the engine. it was a friend of a friends abandoned job. i asked him about it and he pretty much told me the same as you guys. thanks for the quick reply. this is a great site!