Cheapest way to built a 300-350hp small block

-
younggun2.0

younggun2.0

Well-Known Member
Joined
Jan 27, 2012
Messages
4,793
Reaction score
1,520
Location
federal way, wa
going to be starting a 69 valiant build for a driver that my girlfriend and myself will drive pretty often. and she will drive at the drag strip when we go. looking to get the car in the mid 13s with a 904 trans and 3.55 gears in an 8 3/4. im looking to build a cheap and simple small block with 300-350 hp. what would you guys recommend? looking for it to have very mild street manors. I have a set of hooker headers and an edelbrock performer intake and a 650 holley. i think it is going to have to be a 360 because of cost and availability. was even thinking junk yard 360 and leaving the bottom end alone. just new cam, timing gear and oil pump.

lets here your recommendations guys.
 
I am running a .30 over 360. I put fordged pistons in it and a 274 extreme comp cam. Eddie rpm heads and crane roller rockers. I put 300whp.
 
what about stock rebuilt iron heads? mild cam and dual plane intake? think that would make 300 at the flywheel? im thinking that 300ish at the crank would put a light weight abody into the 13s pretty easily
 
Replace the intake with a performer rpm, put mild cam in it say purple sahft .484 or similar from your favorite cam manufacturer and you ar there.
 
simple.

360, 9.5-10:1, xe268h or comparable, stock 1.88-2.02 J heads (bowl porting optional)/rockers, ld340/rpm/air gap, 750dp, headers and decent ignition. Nothing fancy... 330-350hp...

One of those in a Demon with 2.94 gears/2500 converter ran 104mph in 4500ft air at Vegas... it was fat too...
 
Low-ish mileage junkyard 5.9 Magnum, magnum specific Airgap intake, and your carb and headers. That should make 300 hp, and definitely on the cheap. Then, if you want, throw a small cam in the 220 @ .050" range with .500"-ish lift, and there's your 350 hp. Easy peasy.
 
318, 030 over, "302" heads mild port job, stock valves, KB-844 dome pistons, comp XE-274 solid cam, air gap, 1-5/8 headers, 750 mech secondary got a 3200# dart to 13.40's@100 mph at 5800' track altitude. Probably 330 hp, most expensive thing was the pistons($400).
 
Well, 74' low compression A & E bodies ran mid 14's off the floor, so if you can find a solid 360LA that doesn't need a complete rebuild, or maybe will take a berrybush hone and some replacement rings & bearings along with a fresh pump, you could easily duplicate that in the lighter weight Valiant. With the headers and a cam grind to build mid range torque with the low compression, i can see you getting close. I think the carb & intake you have may be a wash, but a little converter, 2800ish, with the right cam and a really good timing curve and tune may get it into the 13's. I'm old school, but in my day, a high 13 second daily driver was a pretty stout car on the street. I'm just thinking a low/no budget type build.
 
i was hoping to pick up a 360 from a wrecking yard and not even touch the bottem end. just straight bolt-ons. if it blows up or dies just pick up another long block and do it again. just trying to keep this on a extremely minimal budget. no port work or full on rebuilds for this one.

how does this sound?

360 out of early 90s pickup/van = 500 at pull a part

eddy performer rpm air gap = 200 new

my 650 holley carb = free

my headers = free

new timing chain = 100

oil pump = 60

gasket kit = 50

misc brackets and parts = 250


comes to $1160 bucks.

not sure what exactly to look for in a 360. i have only played with the old school LA small blocks.
 
66dartman said:
318, 030 over, "302" heads mild port job, stock valves, KB-844 dome pistons, comp XE-274 solid cam, air gap, 1-5/8 headers, 750 mech secondary got a 3200# dart to 13.40's@100 mph at 5800' track altitude. Probably 330 hp, most expensive thing was the pistons($400).
Click to expand...


how much? what kind of shape is the engine in? drop in and go? i work in a warehouse and ship truck line all the time. i could arrange for shipping.
 
bamamopar said:
what kinda heads do you have are thinking of getting? I dont think it should be a problem to get 300 crank hp
Click to expand...

as of now i have no heads. i just have a small pile of small block bolt on parts. have a performer intake off of a 318 and 650 holley carb. set of hooker headers. and a set of 3.55 gears. hopefully picking up a roller 69 valiant on saturday for 800 bucks. trying to build a fun little street car for as close to nothing as possible. just building a toy. want to put my girlfriend in it sometimes and let her feel how cool it is to rumble around town in an old muscle car.
 
My favorite build,budget street toy.Have personally done a la 360.204/[email protected] Performer intake,T/q.188/160 J castings.67 Cues,3.55's 727 with a Road Runner converter.Ran 13.80's daily,best of13.61.
 
Since 90% of Valiant's were /6's, just keep in mind the cost of the misc parts to convert to a small block. Not to mention you'll need a V8 904 trans also.

As far as the early 90's 360, it will most likely have a roller cam in it. While that's a good thing, the cam replacement, if you choose to stay roller, can be a little pricey......like $400ish just for the cam.
 
OldmanRick said:
Since 90% of Valiant's were /6's, just keep in mind the cost of the misc parts to convert to a small block. Not to mention you'll need a V8 904 trans also.

As far as the early 90's 360, it will most likely have a roller cam in it. While that's a good thing, the cam replacement, if you choose to stay roller, can be a little pricey......like $400ish just for the cam.
Click to expand...

how do the stock cams respond to bolt on upgrades? i like the idea of a roller but in the interest of budget if i wanted to step up to bigger lift/duration are they direct swaps to the LA style mech. cams?
 
Response is good, been there done that.

For your goal if 300 or better HP on a stock 360/low compression, do this;

Open air cleaner up top a 650 AVS or Holley carb. A TQ is also good to use. A small primary unit is what I would look for.

Any basic 4bbl. intake. Iron ones are mostly over priced while Edelbrock Performers can come inexpensively. The Weiand Action Plus is also a excellent choice.

Keep the stock heads as is. A mild milling is a plus but mandotory.

Headers help a lot. Use a 2-1/2 pipe.

Cam; with 3.55 gears and a stock tire, a cam of approx. 228intake duration will work. Use a split duration cam (more exhaust duration.) to help the engine get rid of the exhaust gas and extend the RPM range.

I would not exceed a cam intake duration of 228/230 degrees.

If your not going to get a converter to aid the set up, cheat and use Rhodes lifters. Skip the roller cam. Roller lifters are nice but a expensive gain for little power returned.
 
you guys have great ideas. i think i can be done with a 360 for less than a grand. that is my goal. the hunt begins this weekend for a 360 engine to begin with.
 
UOP said:
Low-ish mileage junkyard 5.9 Magnum, magnum specific Airgap intake, and your carb and headers. That should make 300 hp, and definitely on the cheap. Then, if you want, throw a small cam in the 220 @ .050" range with .500"-ish lift, and there's your 350 hp. Easy peasy.
Click to expand...


That was my thought too...
 
I think the cheapest way is with a magnum.
LA 360 are 25 years old, chance of finding a good one in the junkyard is slim.
I bought a 94 360 mag off a member here for $200, when I tore it apart it still had the cross-hatches in the bores, the motor had well over 100K miles on it.

Food for thought.

http://www.magnumswap.com/
 
UOP said:
Low-ish mileage junkyard 5.9 Magnum, magnum specific Airgap intake, and your carb and headers. That should make 300 hp, and definitely on the cheap. Then, if you want, throw a small cam in the 220 @ .050" range with .500"-ish lift, and there's your 350 hp. Easy peasy.
Click to expand...

+1 on that don't rule out the possibility of a solid used Magnum engine, depending on what you find it may be just as economical
 
You will have no problem building the motor for under 1000 but the swap alone gets pricey. I am not sure if it is necessary but I put a new radiator in mine as well which you could get used for cheap I guess. You also may need to upgrade the torsion bars or springs. I wish I could recall everything I had to buy but its been a while and all the papers from the swap are back at home. I would approach it as two builds almost. Build your motor then save some money for the swap. Also since your going to get a new transmission I personally would just cough up the few extra bucks for a good converter. I have the MP .484 cam in my 360 and my converter really helped it out a lot. Good luck and check for parts on here daily.
 
Is your heart set on a 360? I have a really good running 1985 318. Came out of a project I got last year. Have no need for it and can make you a deal on it. PM me if you're interested. Mike
 
You must log in or register to reply here.
-

Back
Top