Help Me Make More Power!

[LuckyHenriksen]

I just got my truck running and driving, and I am already tired of the lack of power. Truck has a 350 and a TH400, with 2000 RPM converter and 3:73 gears. So heres the winter plan-

Pull the motor back out (stock 350 with edelbrock performer cam, intake and carb)

Pop the pan and put in a better gasket

Re-ring

New cam (roller rockers etc....)

New intake

New carb (Blow Through?)

Heres where I need expert advice-

Picking a cam and intake. I want this to be a fun street motor, with as much power as possible. I love high RPM's, but realize that I need a lot of low end power to get the beast to move. What would be a good cam? Somehting with some thumpy idle preferred.... and how about a new intake? I love the look of the Edelbrock Victors, but are they not practical for street use? What would you recomend? And I am looking for a new carb, I want to eventually put a mild turbo setup on this rig and so a blow-through demon is on the menu. Any help or advice is much appreciated.

[thirdstreettito]

Call the cam/intake mani/carb company(s) you want to get the cam from and they can help you ALOT with asking you questions ans such.

[Bob 68327]

If your going to use a turbo/blow through supercharger you will need a cam and intake and carb to work with it . I would start with the turbo set up first and get components that work with it . My 2 cents, Bob

[LuckyHenriksen]

Is there that much difference between a regular cam and a boosted app. cam?

[Bob 68327]

Originally Posted by LuckyHenriksen

Is there that much difference between a regular cam and a boosted app. cam?

Yes the lobe centers on boosted motors are usually around 114 or higher , Bob

[thirdstreettito]

If you want quick power without having to take the engine out, get a Procharger!

[LuckyHenriksen]

Originally Posted by Bob 68327

Yes the lobe centers on boosted motors are usually around 114 or higher , Bob

Ok, ill ask around. Ill probably go with an N/A 'stick for now

[Old Yeller 1970]

A few things.
1. What kind of heads do you have?
2. Demons are great carbs but only on the exact combo they are designed for. Do not buy a Demon designed for a blower, but run it naturally aspirated till you get a blower and expect to be happy with the results.
3. Some setups do OK on the street with a Victor but torque wins stop light to stop light racing and that's almost always done best with a dual plane intake like the Performer RPM.

[LuckyHenriksen]

Originally Posted by thirdstreettito

If you want quick power without having to take the engine out, get a Procharger!

I would love a Procharger! A little out of the budget though.....
Even if I did I think I would still pull the motor cuz the pan leaks like a beast and I would like to make sure the rings are good before making any horsepower with it.


Thanks for your responses guys

[LuckyHenriksen]

Originally Posted by Old Yeller 1970

A few things.
1. What kind of heads do you have?
2. Demons are great carbs but only on the exact combo they are designed for. Do not buy a Demon designed for a blower, but run it naturally aspirated till you get a blower and expect to be happy with the results.
3. Some setups do OK on the street with a Victor but torque wins stop light to stop light racing and that's almost always done best with a dual plane intake like the Performer RPM.

I have some ghetto iron heads, am looking for some alum. ones on craigslist. How are vortec heads? Would a 650 street demon work well? I hear ya on the single vs. dual plane, its quite the controversial topic. I think I would be best to go with a Performer RPM also

[Old Yeller 1970]

Originally Posted by LuckyHenriksen

I have some ghetto iron heads, am looking for some alum. ones on craigslist. How are vortec heads? Would a 650 street demon work well? I hear ya on the single vs. dual plane, its quite the controversial topic. I think I would be best to go with a Performer RPM also

Vortec heads make great power but have issues when the cam lift gets too big requiring extra machining on the heads.

Speed Demon 650's only work with cams at or above 230@.050". That will give you plenty of thump. (I oughta know.) But that's not compatible with a 2000 stall torque converter and requires a good set of heads to flow that big a cam shaft.

You'll want a smaller cam to match your torque converter in which case a Road Demon 625 is probably your more likely choice. I had the RD 625 when the engine still had the stock heads, slightly better than stock cam, Edelbrock Performer intake and headers/dual exhaust and can testify that it was far supperior to the Q-jet with respect to power. I gained quite a bit more off the line torque and top end HP.

I think the type of cam the works best with a 2000 stall torque converter (I'm a manual guy so others may need to chip in here) is something like Comp Cam's 268H. IIRC it has 218@.050" on the intake. Can't remember the exhaust right at the moment. And they work great with the RD 625. I think Vortec heads will work with it without extra machining but they have small combustion chambers and will probably increase your compression too much so I'd be cautious about it.

[LuckyHenriksen]

Wow I need a neighbor with as much wisdom as you
You have some very good advice and I thank you for sharing it. I am really not looking to put alot of money into this motor, I want to go LS- based in the future. Maybe a basic cam upgrade is all I need. I just feel that the engine has so much more to give, it just needs a little help. I will look for a nice street cam and Air Gap intake. I would also like to switch over the HEI ignition, I have an old dizzy that I will rebuild, what else do I need?

[Old Yeller 1970]

Just keep in mind that the limiting factor in making power on an otherwise stock engine is the heads. My original heads were 441 castings which make good torque. 882 and 462 heads are even better. But other stock heads can really kill a camshaft's ability to make power, so before you sink a lot of money into a new cam you might want to pull your valve covers and see which castings you have.

What carb are you using now?

[PanelDeland]

You may want to pull the motor before you spend your money on speed parts.If the engine isn't up to par as far as rings,bearings and valve seal you will probably still be disappointed with it.
As stated above the heads are pretty much the limiting factor.I hear a lot of people touting the vortecs but I really think that the aluminum aftermarket is a better deal.Even budget heads are going to be much better than vortecs and for a few dollars more they just make sense.

[Old Yeller 1970]

Originally Posted by PanelDeland

You may want to pull the motor before you spend your money on speed parts.If the engine isn't up to par as far as rings,bearings and valve seal you will probably still be disappointed with it.

Before pulling the engine, I would suggest doing a compression check which should verify the condition of the rings and valve seal and if you have good oil pressure then the bearings should be good too.

[LuckyHenriksen]

Originally Posted by Old Yeller 1970

Before pulling the engine, I would suggest doing a compression check which should verify the condition of the rings and valve seal and if you have good oil pressure then the bearings should be good too.

Ya I was just thinking about doing a comp. check. After I check all the cylinders, is there some formula to put it into a ratio? such as 9:1?


The carb im using is an old Edelbrock 600. It seems to work OK but its pretty beat up

[kcjones]

I'll third the idea that it's all gonna come down to heads...although it may sound corny (and like I'm trying to sell you something), buy a combo head/intake/cam setup. Match your carb & headers to that.

Don't use stock vortec heads with a 280+ adv dur cam, or use Performer RPM heads in an engine you're afraid to spin past 4000 rpm. Don't use an RPM intake with a little 262 cam and stock heads (well that one probably isn't so bad, but you see my point).

Heads/intake/cam all work together. Get those to match the kind of driving you're going to do, make sure the converter & gears are a close fit, and you'll be happy.

[LuckyHenriksen]

Thanks ive been searching out some different heads. Hopefully I can find some affordable ones! How about ignition? Any advice on what to run with my rebuilt HEI?

[Old Yeller 1970]

Originally Posted by LuckyHenriksen

Ya I was just thinking about doing a comp. check. After I check all the cylinders, is there some formula to put it into a ratio? such as 9:1?

The carb im using is an old Edelbrock 600. It seems to work OK but its pretty beat up

The compression check won't give you the ratio. What it will give you is the PSI each cylinder is holding. IIRC, 120 PSI and under is bad news, 150 PSI is average, 180 PSI and up is like new/high performance.

The only way to know your compression ratio is to find out what size valve chambers are in your heads which can be determined from the casting numbers. Technically you also have to know what kind of pistons are in the engine but usually a fairly accurate guess can be made by just knowing the valve chamber size.

EDIT: About the carb, IMHO Edelbrock carb and best performance don't belong in the same sentence. A RD 625 will make a noticeable difference by itself with no other upgrades. My brother has a '75 350 that came with a 600 Edelbrock. I gave him my old RD 625 and he can testify to the difference in performance.

Originally Posted by LuckyHenriksen

Thanks ive been searching out some different heads. Hopefully I can find some affordable ones! How about ignition? Any advice on what to run with my rebuilt HEI?

You aren't going to need anything beyond a 50,000 volt coil. At this stage of your build I wouldn't bother with MSD ignitions and the like.