i know i have said this befor but go to comp cams web site and download their cam profil program its easy to use and they recomend cam choices for all kinds of combs they even have dyno numbers for each cam/heads/intake/carb/etc combo that u might choose and these numbers are suprisingly accurate

 

You need XE262, with your combo. I am all stock except test tube. I have XE250, like your cam. Its a RV towing cam, for good gas milage, It has no guts above 4000 rpm. Just my Thoughts

 

I like you had some issues with my car, took it to a mechanic and was told that they would have to rebuild the heads. I took it upon myself to just rebuild the top end instead.

I Didn't go with a top end kit, which I wish I had. I instead went with summits cast iron heads (remakes of chevy 1960's performance heads) and a Comp HE268. I stayed with the performer intake and a edelbrock carb, just to keep it all under the stock hood.

The cam that you have stated seems a bit on the small side, not allowing the heads to truely make the power they could. The XE series cams I have heard nothing but good things about and I like my comp cam. I wish now that I had put a slightly bigger cam. We'll see if opening up the intake side once I get a new hood will help my need for more power.

Is this it for you? do you plan on putting anything else on the car... forced induction maybe? That should also be thought about when sellecting head/cam combos.

hope this helps.

 

Why not a hydraulic roller cam?

 

lots of great feedback - Thanks all - I already know I'm going to take my XE250 back to Jegs to see if they will let me exchange/reorder the 262 cam. I have learned you need to be careful who you talk to there, as some of there emplyees are pretty knowledgeable, and some aren't. Service and support has been good there, all the same.

cam cooper - I actually did download that program, and have been playing around with it - good suggestion.

1980 blue L48 - 63Mako suggested that same cam, and I have done some homework myself (partly with that program, partly reading/researching stuff on my own) that validates the XE262 choice if I stick with a flat tappet camshaft.

74moneypit - your feedback (along with others on this thread certainly does help, very much appreciated.

jim2527 - I thought about the roller cam, and if I don't actually purchase the XE262, that may be the path I choose - but it's hard to find a roller cam I can use w/out machining the vortec heads I have. Most of the ones I have seen so far have a lift of .500 or more, plus the addtional cost (I have a budget I need to stick to). It's not out of the picture yet, though.

 

if u get into the program alittle deeper u will find that u can enter the heads that u are thinking of buying(what i mean is their advertised flow numbers) and that does make a diff.if u are like us we get numbers from flow bench so we have actual flow numbers, but the program lets us look at cam grinds before we buy that grind.ps any one looking into 4-7 swap cams dont waste your money.

 

SO - coming back to this project after a couple months now.

I decided to walk away from any immediate action, since the car is running relatively well, and I really wanted to drive it this summer (and I am!).

Since I last posted, I've spent a lot of time researching, reading and assessing advice I received here (all of it good, just trying to nail down a plan for my car).

Here's where I'm at:

Decided to NOT rebuild current motor right now. Instead, I found an old 4-bolt main, 010 block, with crank/pistons/heads intact. I decided I really wanted to go through the entire motor, take my time (and with plenty of advice) start a slow, methodical build of my own.

I've got a freind that builds engines and drags near me who can help coach me through the things I haven't done before, so I'm reasonably confident I can end this project with a pretty fun driver.

It's still a "budget bild" so I'll look to recondition anything worthwhile out of the bottom end, but build the top end as I (more or less)originally thought.

Here's the high-level, top end plan I settled on:

Vortec heads
Comp X4258HR roller cam/lifter retrofit kit
Edelbrock 2116 intake
Rebuilt Qjet (Having it rebuilt by Cliff Ruggles now)

Doing anything with that is still a little ways off, though - so I just finished tearing the shortblock down, and will cart it off to the machine shop early next week, to determine what can be reused and what needs replace. Will get the block bored, decked, cleaned and magnafluxed, the rods reconditioned (hopefully) and the crank inspected. Obviously, will need new pistons/rings...

Already figured out I'll have a few unique challenges as I get deeper into this, though:

1 - Was planning on using a Cloyes aluminium timing cover with the adjustable cam button built in - There are clearance issues with bolts on back of the water pump I currently have - simple solutions/suggestions before I start grinding bolts (aside from changinng to a different timing cover, that is my last choice for the time being...)?

2 - Temp sender won't fit the vortecs (relocate...?)

3 - I am partial to the old style HEI with vacuum advance in my 79, mostly just because I understand it well enough to work with it. I am wondering if there is anything I should at least consider doing here?

4 - Hood clearance should be ok, using a drop base cleaner, and I can go to a 2 inch vs a 3 inch breather filter (not using the stock air cleaner now).

Any useful advice or things to consider on these points? Other points I've not mentioned?

I'll post pics once I get the block and parts back from machine work, if anyone is interested.

 

Either the stock air filter or a drop down will work just fine. I have this arrangement in my 76 (with vortex heads and the stock QJ...
Reddog76

 

A few thoughts.

A cheaper overall route might be to find a complete pull-out late(r) model Vortec. You'd get all the factory roller-cam components and the bores and rotating ***'ys are typically in great shape. Just a thought.

Double-check on the price of aftermarket rods before you pay for resizing the stock rods with new bolts - you might be surprised. Ditto on machining the crank - you can often get a new aftermarket crank for about what it costs to machine the stock crank...and if you're replacing the crank...it might as well be a 383

For the Vortecs, I've tried a few different routes with different senders, etc. and finally just settled in on drilling/tapping the hole for the stock sensor. Your shop can do this quick and cheap if you don't have capabilities to do this at home.

 

Billa,

I do agree that finding a complete vortec engine would be cheaper - except I already have the older block/assembly...

I appreaite the advice on reconditioning the rods/crank - I will compare prices. The machine shop I'm working with is pretty reputable, and have heard good things about working with customers to compare both new and reconditioned hardware. If cost is even close, I'll probably go new.

Thanks for the feedback/confirmation on the air cleaner, Reddog76, that's on item I can assume is good to go.

 

Sounds like a good shop

 

They hav a good rep - tend to be a bit slow, but that's a good trade off for relaibility and quality.

I hope that within 2-3 weeks I've got everything back, all major components purchased, everything properly machined and ready for assembly, and posting pictures of the initial assembly. Still won't have my carb till this winter, so I might as well take my time...

 

I would stick with the HEI. I pulled my distributor apart and cleaned/inspected everything and upgraded my coil, electronics and curve kit from Pertronix, then followed Lars paper to shim distributor to stabilize timing. Finally I followed Lars and John Hinkley papers on tuning for performance per the above timing sticky. If nothing else, shim and recurve your HEI.

I just finished my first top-end rebuild and have been driving my vette all summer (first summer in 5 years the car wasn't apart). It runs so good now and doesn't run out of steam like it used to. I'm doing my motor in phases as time and $$$ dictate. Next will be to replace the bottom end and put a 383 rotating assembly in it. Man, I can't wait to see what that does to the performance.

 

I suspected that going through my distributor might be the best option. I had my timing curved very similar to what I've read about lar's method, and can feel the results in daily driving - so had planned on that to some degree.

This helps confirm I've got a good base for my ifgnition system. I guess I might as well give it a good going over when I pull the L48 out for this new motor (the "while I'm at it" list is beginning to grow...)

I've had that 383 idea in the back of my mind lately, but kinda have a plan to follow for now. I would not say it's out of the question yet, though... I'll just wait to see what the machine shop says about my existing crank first...

 

I had a lot of good ideas and suggestions in the course of this thread - I thought I would circle back and post where I ended up.

I just finished up a prety long, extensive projeect (for me and my skill level anyway).
As I mentioned before, I decided to just build a fresh motor - was not looking for a serious street machine, but a car that's fun to drive, looks and sounds good, and is just not a total dog like my tired L48 was.

So I had soem experince as a "shade tree" mechaninc as my Dad always said - but had never been deeper than a carb, water pump or starter swap. I decided I would teach myself to build a decent motor.

I Read a lot of stuff, from articles on the web to soem books by Dave Vizard (How to build a small block on a budget - part of that didn't really stick, since I went over budget).

On New years day, dropped the new motor in, and have been tinkering with timing and carb adjustments - here are some pictures of the build and swap...

[IMG]C:\Users\Jim\Desktop\Engine Pics\IMG_20100923_193018.jpg[/IMG]

[IMG]C:\Users\Jim\Desktop\Engine Pics\IMG_20100926_100855.jpg[/IMG]

[IMG]C:\Users\Jim\Desktop\Engine Pics\IMG_20101008_104752.jpg[/IMG]

[IMG]C:\Users\Jim\Desktop\Engine Pics\IMG_20101207_170529.jpg[/IMG]

[IMG]C:\Users\Jim\Desktop\Engine Pics\IMG_20101121_192609.jpg[/IMG]

[IMG]C:\Users\Jim\Desktop\Engine Pics\IMG_20101231_153301.jpg[/IMG]

[IMG]C:\Users\Jim\Desktop\Engine Pics\IMG_20110106_185718.jpg[/IMG]




Have to say I'm pretty happy so far - I'm still in break-in and tuning mode, but is a ton quicker than my old motor.

 

Will post pictures shortly, having some issues with uploading at the moment....

 

What's the scoop? What did you end up building?

 

I did - bought an old 350 block, wnt with a new crank//rod/piston assembly, plus the same vortec heads I had, and a roller cam.

I was pretty pleased, especially since it's my first real engine build.

It's what I would call a mild build, but much quicker than the stock, base L48 engine. Also upgraded the exhaust to Hooker side mounts, converted to elelctric fan and am now in the middle of tuning the timing/carb. Just set tiking last night per the "Lars method" I've read so much about on the forum. My edelbrock Q jet is next, but I won't spend a lot of time on that - I actually have my original Q jet being rebuilt by Cliff Ruggles, hope to have it in hand my Feb. 1st.

 

Sounds like this upcoming summer will be a 'blast' for you. In the future, if you want more grunt off the line, swap out the 308 gears.
.355 are nice for hwy/street......I roll with 370 myself. I ran .373 for over 10 years in my first V8 equipped daily driving street machine. Loved it.

 

I actually have 3.55 gears in it - but have been thinking that next winter might be a toss up between paint, or trann/rear end work...

Would I see or feel much difference going from 3.55 to 3.70?