Vortec 350 Build, am I doing it right?

[chiggins]

To start off, I am very much a novice at engine building, and this will be my first real build. I'm just trying to do the research and get some input, so I know I'm picking the right combo of parts that will get me what I want. I'm looking for any feedback from guys that have some real experience with this and appreciate any sort of response.

I recently picked up a '98 L31 block for cheap complete with the Vortec heads (062 I believe) and roller cam. I'm wanting to build a little torque monster out of it to replace the tired old 307 in my '68. I've been doing my research and slowly compiling a parts list for it. My plan is to build a healthy, reliable, and powerful little motor for my money, with lots of lower end torque. Here's what I have so far:
- COMP Cams CL08-412-8 Xtreme Energy Cam; I picked it out for its low-end torque and power capabilities, and was confirmed by Comp that this was the right choice
Specs:
RPM range: 1,200-5,200
Duration @050: 212/218
Lift w/ 1.5: .487/.495
LSA: 110
- COMP Cams Magnum Steel Roller Tip Rocker Arms and COMP Cams Hi-Tech double roller timing set
- ARP head and main studs
- Power Products knock-off Edelbrock dual plane intake, good for 1000-6000 rpm range
- Melling HV oil pump, thin steel head gaskets, and other assorted goodies

The goal is to have about a 9.5:1 compression using the thin gaskets. To accommodate for the higher lift, I will be getting Alex's Parts' beehive spring kit that allegedly allows for .500+ lift without modification to the heads.
link: https://www.alexsparts.com/new-vorte...-130-lbs-seat/
Alongside the springs I will install screw-in head studs to allow the higher spring seat pressure.

Fuel delivery will be from either an Edelbrock 600 or 650; I have both available plus tuning kits to find the best fit. The engine will be backed by an NV3500 5 spd, and I intend on running headers with an H-pipe and single boom tube for exhaust. I plan to run perhaps a 3.73 locker in the rear some time down the road. Wheels are about 26" in height.

I've already gone through and cleaned up the block myself. Oil passages are smoothed out as well as any other ridges in the block casting. I just need to send it to the machine shop and have them do my cam bearings, honing, and final block cleaning. I intend on doing the rest of the building myself.

My power goal is to have 350+ HP and 380+ torque. I feel this is attainable based on what I've read for similar builds. Is this a good level to expect or is it wishful thinking?

Again, I appreciate any sort of feedback, either telling me what I need to fix or that I actually am gaining an ounce of an idea on what I'm talking about lol. I'd love to hear about similar builds and what you guys did to make good power.

Cheers!

[PGSigns]

Let the machine shop check the block. That will tell you if it needs bored or the decks squared. If going with main studs have them install them and check the line bore. Did you get the self aligning rockers for the Vortec heads? After going through a couple of intakes on the L31's I have found the Super victor a better intake than the dual plane. Mine runs very well with it. I would go with a holley 670 street avanger for a carb. I had issues with my 66 with vapor lock with the edelbrock and the duel plane intake. You wil like a rear tire about 28 to 29" high. 26 is kind of short.
Jimmy

[chiggins]

I'll definitely have the block checked out by a machine shop and consult with them about anything that should be handled by them.

The rockers I picked out were COMP magnum roller tip rockers that are self aligning. If I'm able to open up my budget a little I'm sure it would be better to go full rocker.

I do recall reading about guys having vapor lock issues with the edelbrocks due to the bowls getting hot. Thats just a bridge Ill have to cross if I come to it. I have the intake that I do because it popped up on FB marketplace for cheap.

Does the rest of the build at least sound like solid power potential? Im hoping to get as close to 400 as I can.

[Dead Parrot]

The Eddy bowl problem is easy enough to solve with a thermal spacer.

Don't forget mundane things like new HEI distributor, making sure the radiator is up to the new motor, fan and fan clutch or electric fan setup, transmission cross member, new motor and transmission mounts, etc.

Amazing how much money things like that can eat.

Driveshaft length?

If you still have the external regulated alternator, be a good time to swap to an internal regulated version. Especially if you go with electric fans.

What is the planned end use for the truck? Street cruising, daily driver, mainly highway, towing?

[tdangle]

with those cam specs you should be right on target. The GM performance crate engine I'm installing right now is rated at 357 HP and 407 ft/lbs of torque with a very similar cam, 9.1 compression Good luck with your build

[truckster]

What transmission do you have? The Vortec will require a different flexplate or flywheel.

[biketopia]

I'd have to pull the cam specs but, the LT4 Hot cam is a great cam for the Vortec engines. I ran one in a carbed application in my camaro for a year until I swapped to my 427. There are a bunch of reviews and articles on line on that exact build and they make 400hp all day and are very street able. The link to the spring kit is dead, I used stock a set of LS2/6 take off beehive springs and a comp retainer to give me plenty of clearance with the hot cams lift and I was using 1.6 rockers. I didn't touch my heads other than clean them up. I can dig up my notes if you are interested but here's one link with dyno results. http://www.superchevy.com/how-to/678...cam-355-build/

[chiggins]

Originally Posted by Dead Parrot

The Eddy bowl problem is easy enough to solve with a thermal spacer.

Don't forget mundane things like new HEI distributor, making sure the radiator is up to the new motor, fan and fan clutch or electric fan setup, transmission cross member, new motor and transmission mounts, etc.

Amazing how much money things like that can eat.

Driveshaft length?

If you still have the external regulated alternator, be a good time to swap to an internal regulated version. Especially if you go with electric fans.

What is the planned end use for the truck? Street cruising, daily driver, mainly highway, towing?

Ive already got a pretty new billet HEI. I intend on running a serpentine system out of a 90's truck minus AC. The radiator should be just fine, it was perfectly capable with the 307. As for usage of the truck, it'll just be a weekend warrior and occassional grocery getter. But I want it to be reliable enough to daily drive if I see fit.

[chiggins]

Originally Posted by truckster

What transmission do you have? The Vortec will require a different flexplate or flywheel.

The truck currently has a saginaw 3 speed in it, but I just picked up a complete NV3500 plus driveshaft, slave and master cylinders, and pedal box out of an s10.

[biketopia]

Also for your application stock main and head bolts will be plenty sufficient. If you wanted some added piece of mind you could upgrade to ARP bolts, but not really a need to stud it.

[Tom]

-Main studs are way overkill and require a line bore, I'd skip that. Head studs really aren't needed either, but at least they don't require machining to run.
-Roller tip rockers don't make sense. Step up to real rollers or save money and use stockers.
-using a valves pring kit rated to .500 and using a cam that gives .495 is living dangerous, your going to have to make sure its all good before running the engine
-9.5:1 is pretty much stock compression

Otherwise it sounds like a nice simple setup.

[Captainfab]

I would skip the HV oil pump and just go with a standard volume oil pump.

[Ironangel]

Have those heads pressure checked for cracks, Vortec's are notorious for cracking heads...A junkyard indicator is if the motor had antifreeze instead of water in it when you crack it open...I agree with the HV oil pump not being necessary, especially with a stock roller valve train. I also agree with the head studs being overkill, bolts will be plenty good with cleaned threads and a high temp thread sealant applied to the threads and ARP Ultra-Torque lube under the bolt heads...

[toolboxchev]

Depending on the spring in the oil filter adapter, the HV pump can send all your oil past the filter.

Not good. 4 types of pumps

High Volume, High Pressure
High Volume, Low Pressure

Low Volume, Low Pressure
Low Volume, High Pressure

Dont ask me how they do it???? Match the viscosity of oil for the bearing tolerances and type of driving.


Did I miss something?

[chiggins]

Originally Posted by Ironangel

Have those heads pressure checked for cracks, Vortec's are notorious for cracking heads...A junkyard indicator is if the motor had antifreeze instead of water in it when you crack it open...I agree with the HV oil pump not being necessary, especially with a stock roller valve train. I also agree with the head studs being overkill, bolts will be plenty good with cleaned threads and a high temp thread sealant applied to the threads and ARP Ultra-Torque lube under the bolt heads...

Before buying everything and diving into the build, I was going to do a DIY magnaflux or have a shop check them out. And I did read up on different pump characteristics, and for my clearances and use I'll stick with a standard pump, with maybe a slightly higher pressure spring like in the Camaros I believe.