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Need Advice on Engine Build Up

7K views 51 replies 20 participants last post by  BIGSHOOTER 
#1 ·
Hi, I am 16 and have a '78 Malibu that has a 305 in it, but not for long. Just recently I purchased a 350 4 Bolt Main out of a early 70 pickup. My dad and I were planning on putting 375 fueled heads, 268 Crane Cam (and all matching valvetrian parts), Hooker headers, a 600 Edelbrock Carb, Performer Intake, Scat Crank, Boring it .030 over, High Performance Rebuild Kit, and Etc. Plus we got to get a 350 Turbo tranny and between a 3.23 & 3.73 gear. So is there any other parts I might need to get or any advice? Also about how much HORSEPOWER will it and have, and what should it run in and 1/8th? I was hoping to get 425-450 HP so I'll be fastest at school.

Sorry I meant a 266 Crane Cam
 
#2 ·
"High performance rebuild kit" what type of pistons? flat top, domed, etc.. forged, hypereutectic etc..compression on the pistons?

I just built my first motor BY MYSELF. its 78' 350 4bolt 9.35:1 speed pro hyper flat tops, vortec heads, comp magnum roller tips 1.52, comp XE 262, performer rpm airgap, Holley 650 double pumper, cast crank, reconditioned rods.

It makes around 350hp
I highly doubt you would make 400+hp. If its street you are looking for more tq really.

If this is daily driver you don't want over 10:1 compression really since you will be getting into pump gas friendly issues.

-Eric
 
#3 ·
I`m in the same boat...I`m rebuilding as we speak. When starting from scratch make sure all machining is done. Along with boring or honing your block.....MAKE SURE you balance it, keep your compression ratio around 10 to 1, you must have a tight quench . I skipped some of those important things my last time and my high dollar bolt ons were nothing....just a slow car.I am not kigging you, parts alone dod not make the car go.....the machining is a must also. Pay attention to the machining part of the rebuild , and I`m sure all of the ole timers on here will agree. I wish I had this advice before. Now I`m back at the machinist spending twice as much.

Good luck!
 
#4 ·
First off, be forwarned of many "high performance rebuild kits" the pistons that come in these kits have .020 off the tops, which kills quench and compression, My suggestion would be to get the teflon coated skirt speed pro pistons off ebay, the buy it now price is around $135, this is for a 4 valve relief flat top with coated skirt. Ebay is ate up with pistons, only most of the plain jane flat tops have the .020 off the tops, avoid these. set your Quench distance of around .045 to .040, keep the compression around 9.5:1. I`d run a comp cams H268, it`ll give a lopey idle and won`t kill low end torque. I would get the basic rering kit from Northern Auto parts that includes bearings, rings and gaskets.
 
#6 ·
First off, close to stock weight? That doesn't make any sense. Each piece of a rotating assembly is balanced individually, and stock Assemblies are not balanced. Second, horsepower and torque are mathematically derived from one another, you cant just build a motor with "a lot of torque."

To make the 400 horse you need a bunch more cam, aftermarket heads and some more compression. Its cool you and your dad have a project to work on together. Put some more cam in it so you can hear it when it idles, it will put a smile on your faces!

K:thumbup:
 
#12 ·
Yeah but on cam and carb, intake etc.. That can affect your tq.
The "close to stock weight" i really don't know much about..
My friend told me that who owns a machine shop and is running a 10.20 in with his sbc so i think i'll listen to what he is saying.

-Eric
 
#16 ·
Vortec heads are probably your best bang for the buck i picked mine for $480 brand new complete shipped to my door. But they can't handle above a .470 lift with STOCK springs, self-aligning rockers you need will cost you more than regular rockers, if you want to run roller-rockers you gotta machine them for guideplates. You can get different springs but after .5 lift the flow numbers on the vortecs go down..for around a 400hp build up have you considered World Sportsman II heads? good price, good performance matched with one of comp's XE grinds?

-eric
 
#18 · (Edited)
just because the heads are off a 375 HP 327, doent mean youve got 375 HP. the old fuelie heads were the hot ticket in there day, but there day has long passed.

The 375HP 327 was a great motor, but first off 375 HP was a gross rating, coulda been more, coulda been less. It was also a high compression high reving solid lifter cam motor, not a mild hydrulic cam like the H-266
Just for giggles I punched your plan into DD2000 & used the asumption that youll have 9.5:1 compression & heres what I came up with.
peak HP= 354HP @ 5500RPMs
peak TQ= 394 @ 4000 RPMs. actually not to bad of a combo considering that its gonna make good power & never rev past 5500 RPMs. John
 
#19 ·
... WHich means you'll be putting roughly 300hp to the wheels. I think you'll be surprized how fast the car is when you get it together! Don't worry about numbers. People fudge horsepower ratings all day long, I would just build the motor you want to build and be done with it. You have a nice setup, and I promise you you will like it and you will beat almost anything on the road.

:thumbup: K
 
#23 ·
I agree with killerformula. Build the best engine you can given your budget and you'll be happy. Just remember it is your first engine build and you'll learn a lot a long the way so you can build a higher hp eng the second go around. If you're anything like me you can't get enough power. Don't get stuck on the numbers as you'll only be disappointed.
 
#25 ·
Just put a SMALL hp shot of nitrous on it (100-150). That should get u to where you want to be and keep it drivalbe if you're taking it too and from school. Your dad will get tired of givin you gas money if u try gettin 450hp all motor out of it, trust me, i have a 383 s-10 that's puttin down about 500 right now (it's all roller with an eagle competition assembly). But it is the most fun vehicle I've ever had, and it's about the only thing that will keep up/outrun these mustangs around town.
 
#26 ·
im going to go ahead and say i agree with big block bill i dont like some kid just learning how to drive flying around in a 300 hp car.
and i sure as he*^ wouldnt tell some 16 year old that 300 isnt enough throw a shot of nos on it.
my first car was the slowest thing i ever drove and i still almost killed myself on numerous occasions
 
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