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400 heads

1K views 9 replies 2 participants last post by  gmtony55 
#1 ·
Ok guys, I read a lot of info on Vortec heads and they sound great. I have an uncle who owns a tow company and sometimes has total losses he can part out so getting a set would not be that hard to get. I have a 1971 400 all stock,heads to match. 511 block and I think 493 heads. I want to end up with a daily driver with a little power and still some fuel economy. because I already have rpm intake for the stock heads I would like to go that way. I think with vortec I would have to buy an intake that will allow a carb. What do you guys think? my friends all say buy a crate engine and sell 400. But me and my boy want to build it together.
 
#2 ·
The machine shop I talked to said he would go through my heads and rework them for $125.00 each. but If I end up with junk thats not good but on the other hand if I had a lot of money I can buy plenty of other heads Im sure. What would be a good cost effective way?,in your opinion.
 
#3 ·
vortec heads are great for small engines to make decent power.The flow is good when used with a small low lift cam.If you dont want much over 400 hp the vortecs work great.If you build a performance 400 cube engine then 400 hp is no big deal.If you want fuel economy then HP is not what you are looking for.$00 cube engine may not be the correct size engine

If you have a specific goal in mind,post some details,IE:
vehicle
mileage desired
use of vehicle
or power required and application.
 
#4 ·
ok. my goals are 16mpg and 350 hp or so. I will use almost everyday. It is going in my 1983 elcamino which i drive everyday with a tired 305 in it. I get 15.8 to 16.0 mpg now but it doesnt have too much get up and go. It will spin the tires but they are small tires and I plan to go up a size to 15". I have a 200 trans and I think gear ratio is 2.41..I feel pretty strongly if I put this 400 in I will be pleased with the difference from now but I dont want someone saying you should have asked because for another $100 bucks you could have done this And had plenty more power or gas mileage
 
#5 ·
9:1 CR,you pick the heads
180235-10 NA 266 270 213 217 .485 .495 110 106 Hyd. Hyd. 1
1000-4800 Fair idle, good low & mid-range performance increase.
cam like this or smaller
street master intake
edelbrock 600 or equal
1 5/8s headers
this with the 2.42 gears will work nicely and still make a high 14 second pass.
mileage will depend on car/tires/suspension. 16 plus to the U S gallon should be very easy
 
#6 ·
9:1 CR,you pick the heads
180235-10 NA 266 270 213 217 .485 .495 110 106 Hyd. Hyd. 1
1000-4800 Fair idle, good low & mid-range performance increase.
cam like this or smaller
street master intake
edelbrock 600 or equal
1 5/8s headers
this with the 2.42 gears will work nicely and still make a high 14 second pass.
mileage will depend on car/tires/suspension. 16 plus to the U S gallon should be very easy
Here is where I show my lack of knowledge. 9:1 cr I think mine with dish pistons is 8.5 to 1..next that whole row of numbers is greek to me,please explain. I have an edelbrock rpm performer intake. and you say 2:41 is ok or did you mean to put 3:42. thanks for your patience.
 
#7 ·
( I have a 200 trans and I think gear ratio is 2.41..I feel pretty strongly if I put this)
the 2.41 gear is ok for gas mileage,just dont expect super fast 0-60 times.
the cam I posted was just an example of a cam that would rev to 4,800 rpm in a basic 350
in a 400 it would likely start to cap out about 4400 rpm.
The low rpm power is good for tall gears and more mileage oriented than a long duration cam.
you will need to change the pistons if you rebuild the engine???
decide on what heads you want to use,then calculate the piston size to give you 9:1 compression ratio,,ie,if you use 76 cc heads like the stock 400s came with,then the stock replacement pist will give you around 8-9:1 cr ,depending on what exact pistons that you order.

what ever decision you make,you will want around 9:1 cr,small cam,small carb,headers etc
 
#8 ·
Thanks for your reply. this engine ran good when it came out and I was tempted to put it back in without taking pistons out. but it set up a while and I figure I would have it honed and re-ring it but I am planning to keep same pistons. I get the jist of what you are saying and mid 14 second pass would be about what I am shooting for.
 
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