It's Time
Senior User
Joined: Jun 2002
Posts: 263
Likes: 0
From: Blackville, SC, USA
It's Time
I'm finally getting ready to build a serious 400. I'd like some ideas on where to begin. I have several blocks to chose from and a couple sets of heads. I would like to get my CR up around 10 or 11:1 I think. Then I would be able to use a pretty radical cam. I plan to have the crank balanced and some other odds and ends. It's really kind of up in the air right now. I'm hoping to get some good info from you guys to give to my machinist. He has never built a high performance 400. Any info will be appreciated guys.
Freshman User
Joined: Aug 2002
Posts: 25
Likes: 0
It's Time
a couple questions
what do you plan on using it for?
street or strip?
with 10:1 CR you'll have to use some kind of racin fuel
i hear that aussie 3V heads are the best out now but expensive...i'd just 3 angle some solid 2V heads
get some TRW or anyother name brand pistons (dont go over 9.5:1 or you wont be able to run on pump gas)
i like the Weiand X-Celerator manifold with adapter plate
Speed demon 750cfm carb.
if your goin with like a 280H from Comp. you'll need a custom stall coverter i plan on using the highest with a stock converter which is the 268H grind from Comp.
if you want to get into millin and things you'll need to talk to Shazam he has that stuff down pat more than i do
just my 2 cents
what do you plan on using it for?
street or strip?
with 10:1 CR you'll have to use some kind of racin fuel
i hear that aussie 3V heads are the best out now but expensive...i'd just 3 angle some solid 2V heads
get some TRW or anyother name brand pistons (dont go over 9.5:1 or you wont be able to run on pump gas)
i like the Weiand X-Celerator manifold with adapter plate
Speed demon 750cfm carb.
if your goin with like a 280H from Comp. you'll need a custom stall coverter i plan on using the highest with a stock converter which is the 268H grind from Comp.
if you want to get into millin and things you'll need to talk to Shazam he has that stuff down pat more than i do
just my 2 cents
Senior User
Joined: Jun 2002
Posts: 263
Likes: 0
From: Blackville, SC, USA
It's Time
I plan on mud racing with this truck but I would still like to be able to drive it on the street. I already have a Weiand intake but it is the action+ and I plan on keeping it. I am using a Holley 750 double-pumper. I will probably stick with the original heads and make what modifications to them that I can. I also plan to bore and stroke it and balance the crank. I don't know what pistons I'll use because I plan on decking the block and I need to get some dimensions. That is the main reason I'm asking for advice. I need any suggestions as far as how much to take off of the block, what can I do to the heads, what size will the combustion chamber be and so on. I won't be doing the work myself, I'm just getting info for my builder. He has built many race motors but never a 400 and he needs to know which direction to go.
Senior User
Joined: Dec 2001
Posts: 356
Likes: 0
From: space city
It's Time
>What are quench heads?
aussie's, early 4v or boss 302 & 351. to make "quench" work in a 400, you need (besides the different heads) to get the pistons to come up higher than normal, either by using taller pistons or getting the top of the block cut down. but that will make your compression too high, so you need a dished piston. but that will decrease the quench effect, so you need a piston with a special "reverse-dome" or "d-cup" dish that matches the chamber.
if you do some looking around this forum, you'll see a lot of discussion on this topic...
if you do a web search for "quench piston head clearance" you'll find several pages with a thorough explanation of all the in's & out's of quench. then look at some piston specs, gasket thicknesses, and the 400 deck, rod, and crank dimensions and you'll see why there is so much discussion on this subject.
aussie's, early 4v or boss 302 & 351. to make "quench" work in a 400, you need (besides the different heads) to get the pistons to come up higher than normal, either by using taller pistons or getting the top of the block cut down. but that will make your compression too high, so you need a dished piston. but that will decrease the quench effect, so you need a piston with a special "reverse-dome" or "d-cup" dish that matches the chamber.
if you do some looking around this forum, you'll see a lot of discussion on this topic...
if you do a web search for "quench piston head clearance" you'll find several pages with a thorough explanation of all the in's & out's of quench. then look at some piston specs, gasket thicknesses, and the 400 deck, rod, and crank dimensions and you'll see why there is so much discussion on this subject.
