Hey guys, I'm building a 350 to replace the L03 in my '91 RS. It's a daily driver and doesn't need to pass emissions. I already have the roller block and installed an eagle street performance rotating assembly kit with 9.8 compression hyper pistons. I already have a 454 tbi unit with 81# injectors, and plan on upgrading my computer with EBL. I'm just trying to figure out the best part combination to complete my build. Here's the combo i'm thinking of:

Edelbrock e-tec 170 heads with .028 gasket
Edelbrock RPM airgap vortec manifold
Comp cams 268 xfi hydraulic roller- 218/224 @.050, .542/.537 lift with 1.52 rockers
Comp 1.52 roller tipped rockers
Hooker 2460's with y-pipe
Borla 3" cat back (already installed with no cat)
Ignition??? recommendations please
Detroit Truetrac with 3.42's (already installed)
stock 700R4 trans (once it blows up I need to decide between t56 swap or beefed up 700R4)

More info of the build up can be found here: https://www.thirdgen.org/forums/tbi/...g-350-tbi.html

What do you guys think? Please keep in mind that is for a daily driver that will get run at the track just for fun every once in a while.

 

You probably picked those headers because of no emissions, right?

The y-pipe is only 2-1/2" after the two sides join together. You can cut that off and put in a Flowmaster 3" "Y", but by the time you do that, you'll have spent as much as just getting 2055HKR's. Don't want the A.I.R. tubes? Simple matter to cut them off and weld the holes shut. The y-pipe is the best available, might as well start there.

Ignition - stock distributor, aftermarket module, coil, etc.

 

exactly, don't want the A.I.R. tubes cluttering up the engine bay. I have some pretty good fabrication skills so cutting off the tubes and welding them shouldn't be a problem. I'll just have to send them out for jet-hot coating after i'm done modifying them. Should I make little plugs out of something like 16 gauge sheet steel and weld them on, or just fill the hole with weld?

 

Just cut the tubes off at the top of the weld, and weld them shut is what I did.

Check my vBGarage for pics.

 

and then clean up the inside with a die grinders for optimal flow.

 

Yes, I did that as well, just didn't mention it.

 

My tubes screw in with 1/4 npt fittings. Or possibly I'm wrong but I don't think so.

are you talking about the HKRs?

Can I put plugs in my stock manifolds? think i can get the tubes off?

 

Thanks for the replies, I'm gonna go with the Hooker 2055's and just modify them. What do you think of the other parts of this combo? The 268xfi cam looks like it will perform nicely as a street cam and shouldn't be too hard to tune. I've done a lot of searches and haven't found much info on this cam or the e-tec 170's. I haven't heard anything bad about the rpm airgap manifold, except that there is the possibility of hood clearance issues. I have the fiberglass SS hood so I think I should be able to make it work. I will be ordering parts soon, so if you think any of these parts will be an issue, let me know

 

So I called up comp cams yesterday and they recommended the 260xfi cam. When I talked to them a month ago, a different guy recommended the 268xfi. Now i'm torn between the two.

268xfi:
camshaft type: hydraulic roller
basic rpm range: 1800-5800
duration @.050: 218/224
advertised duration: 268/276
valve lift: .570/.565
LSA: 113*

260xfi:
camshaft type: hydraulic roller
basic rpm range: 1200-5200
duration @.050: 210/218
advertised duration: 260/270
valve lift: .560/.555
LSA: 113*

keep in mind that these lifts are measured with 1.6 rockers. If i go with the 268, I will probably go with comps 1.52 roller rockers.

If i go with the 260 xfi, I will be gaining more low end torque at the expense of upper rpm horsepower. I'm thinking I will have enough traction problems with the 268, so going with the 260 will will just make it easier for me to spin the tires, plus lose a little top end. What are your opinions?

Will I run into any vacuum related problems with the 268? (power brakes, cruise control, etc) Will the 268 be considerably harder to tune?

your advice is appreciated.

-Erik

 

I'd say definitely go with the 268.

 

I have the XE270HR cam which has similar specs except 110 LCA vs your 113 and it runs fine on the street, and power peaks around 5500 RPM on mine.

The cam made 310 RWHP & 342 RWTQ with TrickFlow heads, Perf RPM, and street/strip QJet, 1-5/8 Edelbrock headers & 8.6:1 compression.