What do you think?

[speednmark]

Ok heres the deal, i need some advice for my future plans on my truck....its a 1970 chevrolet c/10 with the 350 and a 3 speed....engine is bored .30 over, new 427 casting heads, new cam from previous owner, new carb, new headman headers, stock 3.73 differential, everything has been rebuilt from the previous owner...i'm guessing this truck has around 250 hp. I want to do a new top end: new hydraulic roller cam, new edelbrock alluminum heads, a new intake, and either 2 3/4 in headers or 3 inch headers long tube...ive been told that this will put me at 350hp MINIMUM and possibly up to 400-425 hp. Does anyone have any similiar experience to this and if so what were the results, if not what do u think? Thanx...

[68C15]

Edelbrock does have nice packages that work together. getting 350ish HP is not too hard. instead I would build for torque at trhe RPM you plan to be in most of the time. HP will follow as its a mathemetical derivative.

[MrC1]

I agree. Make sure you match your parts as a system or you'll end up with a pig that doesn't perform well.

2.75-3" headers? Most header collectors are 3", but you'll want the primary tubes to be 1-5/8 to 1-7/8 on a 350.

You may want to play with Desktop Dyno software to get a better idea how the different parts work together for the best combo - especially the cam specs.

Yes, 350hp from a 350 isn't too tough. Any more than that without forced induction and you'll really start to sacrifice bottom end power and might make the truck annoying to drive.

Good luck!

[72MARIO]

Just make sure the 350 or 400hp is not at 5000RPM+++ that would be kinda lame and annoying to drive on the street. Just like what the other said. Having a combo that works together is best for over all fuel economy and driveability.

My 67 with rebuilt stock heads 3 angle valve job, 67 327/350HP cam, Perforemer RPM, 650 Demon Carb, Shorty headders 1 5/8" to 3", with 3" duals is stupid fast. It goes sideways in the 1-2 and 2-3 shift. As well it get's 15+MPG I have 3:73 posi and a 700R. I am sure it's under 350 HP but that good for me.

[speednmark]

if i decided to keep the cam which is new but i have no idea what the origional owner put in it, so well call it stock, and just went with new heads, would i see a difference in performance, and if i went from a 750cfm carb to a 650cfm would i notice a diff.?? speaking of heads, should i go alluminum or casting-iron heads?? it has new heads but i dont believe they are massive by any means....thanx

[Bowtie67]

Seeing that you really don't know truely what you have the best thing to do if you can let the truck sit for a week or two is to go ahead and pull things apart. The cam will have some sort of identification on the back of it when you pull it out. If you have few thousand miles on it or have been beating on it, it wuld also be a good idea to plan on a new timing chain & gears. Pulling the heads and getting the casting numbers off of them will tell what heads you have and at this time you will be able o see what type of pistons you have so that if you need to bump the compression this would be the time to do it with the head swap for picking the proper cam. I am not against roller cams and as a matter fact I wont build another engine without one, but they are an expensive setup, cams are generally around $300 and roller lifters are $400+, you can get complete Hydraulic cam & lifters for under the price of the roller cam alone. The 750 is a little large for a 350, the 650 would be better (not to mention a little better fuel econmy), if your looking for an economy carb go with the edlejunk, if its performance go with a Holley, BG, or Proform model. Headers for a street setup 350, I would stay with a set of 1 1/2 or 1 5/8 and possibly a 2.5 collector, the bigger tubes and collectors would be more beneficial for topend, not lowend tourque.

[speednmark]

i know ive got 427 "big pow" casting heads, how much of a difference between the edelbrock carb and a holley in economy will it make changing it, if i decided to later on go with a hydraulic flat tappet, new heads, and a bigger intake mani would the 650 be big enough???

[special-K]

Just remember,tappets/cam,tappets/cam.They should be one word.Why do you want to change heads?I`m not sure what 427 heads are.What valves are in them?If you`re running stock compression,you don`t want the biggest heads & carb.That can actually kill your performance,as well as economy.A cam can only do so much alone.If you go up in compression you can have a pretty lumpy cam,big ports and a reasonably large(750cfm)and still have decent economy with a light pedal.
Like said,though,I would build for torque at low to mid-range rpms.These are heavy vehicles and that`s your first variable.Once rollin`,it don`t matter and you`ll have the horses to keep it rollin`(without mashing the pedal).