difference in 427 truck motor and car motor

[wuckywuk]

can i use a truck 427 in a car. does something have to be changed. is performance the same. what is major difference. thanks

[MagicRat]

There have been several threads on this. Generally, the truck blocks have a 1 inch taller deck, designed to accomodate heavier, taller pistons and (I think) longer rods.
The heads tend to be small valve, low compression types.

The auto 396 - 427 - 454 heads will bolt on, but the intake manifolds are too narrow and will not fit. The reciprocating assembly is a bit heavier, so the engine builds revs slower

Conventional wisdom says the truck blocks are not suitable for any kind of performance, even if they will fit in your car (due to deck clearance problems)
However, a previous post on the subject mentioned a company that builds performance parts for such engines....... I cannot find the name, though.

[wuckywuk]

thanks a lot magicRat, I will pass up the 427 for now. i am working on a 69 caprice that came with a 427 and just wanted to go back with one.

[MrPbody]

MR,

Just for clarification, the deck is .400" taller on the "tall deck" BBC. You're right about installing it in certain cars. The added height messes up exhaust fitment.

The tall deck is the production block "of choice" for serious horsepower. It allows the use of a .400" longer rod, making a HUGE difference in rod/stroke ratio. The 427 is the better one, as it has the desired 4.25" bore. The 366 has a much smaller bore, but I've seen them bored to 4.25 successfully. ALL tall deck blocks are 4-bolt. I don't know if I've ever seen a true factory 454 "tall deck".

Dart (Big M) and World Products (Merlin) both offer a tall deck "race" block. There's one that is actually .800" taller, usually used for "pullin'" trucks or tractor racers, over 600 CID. Sonny Leonard (sp?) has several packages using tall decks.

Wieand makes spacers that allow the use of standard intake manifolds, both oval and rectangular port.

I agree, in the aforementioned application, a tall deck is not recommended.

FWIW

Jim

[daryl087]

I just built a tall deck engine and i'm very happy with it the crank is forged steel from the factory. and all you have to do is buy longer rods and car pistons change the heads and intake. and i have about 600 hp easy