Okay here is the combo:

4 bolt 496 CI
forged crank
eagle 6.385 forged h-beam rods
S/E forged pistons 12/1
Merlin 310cc Rec. "Grumpy Jenkins" heads
Comp cams 11-772-8
Solid roller LIFT .653 .660
DURATION AT .050 248 254
Comp cams roller springs, lifters and Aluminum rocker arms
milodon 7-qt pan
Holley 1000HP carb
MSD dist. and Digital-6 plus ign.
Dart single intake
C/r is 10.2:1
Hooker comp headers 2"
3 1/2 exhaust (3" tails)with DrGas Xpipe and StraightLinePerformance Mufflers
ATI built th400 and treemaster T/C 4000 st
Moser 9"/nodular case/detroit locker/457 gears/35 spline axles
SSM lift bars and air bags in rear coils
Denny's nitrous ready driveshaft
Nitrous Express Gemini Twin Plate System

I have been abusing :D this setup for 4 years and only had to replace the valve springs once.
I use it street/strip. Several 40 mile (1 way)road trips each year.

Goals:
A little more road worthy
Keep same/better et's (11.2 motor & 10.4 nos-150)
More durability if possible

Ideas:
373 gears, head change?, cam?, isky lifters, different intake?, pro magnum rockers, tranny rebuild, rebuild tc with a little less stall, general rebuild stuff (bearings, machine work, etc).

Need input! There is alot of experience here and I have been reading too many posts. What works for you? Combos? Parts? A little help please...

No one has any ideas? suggestions? Comments?

Oval ports :D RPM Air Gap,3.73-4.10's, you have waaaaaaaaaaaay to much gear and 11-1 comp. max(do you have 12-1 or 10.2-1?)

Hey Robert, thanks for the input. Not sure on heads yet, dual plane intake does not work to well with the bottle on power levels I will use, final cr is 10.2 and I was thinking 373 gears as well. Any other ideas...

Frank,

How's it going? Long time no talk. Let me know when you head out to the track. I'm moving up to Lewisville in the next month or so.

Please ignore all I have to say below since I will have to line up next to you at the track in the future. :D

For the shortblock, I would have everything magnifluxed and put a new set of rod bolts in along with new bearings and rings of course.

I think your cam is just about right for your combo (duration/lift) and what you do with it. Sorry for being lazy and not looking up the part number, but what is the lobe separation? I would go with the Isky Red Zones for added durability.

I think the biggest room for improvement is your top end. The intake you have is a good one, but would work much better with a lot of compression, big cam, and some RPM(gear). I would go with a Performer RPM Air Gap given how you use the car. It will improve driveability and probably pick up ET based on the reports of some of those hear who have done a comparison. I would go with the Rectangular port version on a 496 regardless of Oval/Rect. head. The only bad thing is the Gemini Twin may not work with the dual plane.

Your heads are another area where there should be some noticable improvement. They are an older design. There is a lot of better stuff out there now. At a minimum have the surfaces cleaned up, fresh valve job. If you did have them ported I would try to keep the cross-sectional area and volume down as much as possible. A good set of ported GM ovals will flow better numbers in the low/mid lift and be close at high lift with a much smaller port and better velocity. All of which means more TQ/HP at lower RPMs. If you did something like that you could move to a 3.73/3.90/4.10 gear and still likely see a gain at the track. Having said that I personally would not want to dump a bunch of money in a 30+ year old set of heads. There are a lot of good ones out there. Brodix/AFR/Profiler/Canfield/GM/Edelbrock/Dart. The key with all of them is to use an efficient head with good mid-lift flow. Efficient meaning flow well with as small a port as possible.
The new Brodix Race Rites with a 270 cc Oval port with CNC chamber look to be a very good/efficient head with the exhaust port in the stock location if that is a concern. The AFR 305 "as cast" with CNC chamber would be another good choice. The Profiler 290 Oval is another good choice. Those would be my top 3 choices. The Brodix has slightly better intake flow than the Pro-Filer with a 20 cc smaller port. The Pro-Filer does have a better exhaust port though so that would be a consideration with N2O use. The AFR is a little bigger but flows significantly better than both the Brodix and Pro-Filer on the intake and exhaust side. The AFR's should be killer on a 496 with N2O. Personally I don't think you can go wrong with any of them. It just depends what feature you deem most important.


Who do you use for machine work?

I forgot to mention if you do go to an aluminum head I would consider milling the chambers a little to increase compression and TQ.

What is the cranking compression on your current engine?

Originally posted by 69bigblock:
Hey Robert, thanks for the input. Not sure on heads yet, dual plane intake does not work to well with the bottle on power levels I will use, final cr is 10.2 and I was thinking 373 gears as well. Any other ideas... How much Nitrous are you going to use? Pat musi when he built my motor said 200 shot max from a plate system ontop on my 540. If you are going for more than that you should look into an upgrade to a direct port system anyway, so a dual plane is an option. Im running 10.9-1 with cleaned up 305 cc grumpy rect port heads. 600 lift at 230 duration solid roller. rpm airgap with a 750 speed demon.

Hey Jason, look forward to having you in this neck of the woods. I was thinking the same thing on the intake. From everything I read I will never take advantage of the one I have because I will not be in the 7000+ rpms. My biggest concern of the dual plane is getting the same nos mixture in all the cylinders. I could probably plumb all the runners for a foger setup (read expensive). The lobe seperation on the cam is 110. Isky lifters for sure. I do need to do research on which heads to use. Thanks for info/suggestions. I have not decided on who to use for machine work. There are many horror stories about shops in the area. My friend in his 68 camaro/502 just needed it freshened up and he has had to pull the motor twice already and take it back to the shop. So I will need any info on shops in the area.

Doggy, I will probably not use more than 200 shot of nos. I am using the grumpy rects right now as well. I could use losing a little weight of the car(aluminum) and if the heads flow better, than all the better.

I am listening....

Frank

Frank,
On the heads, I feel the AFR is the best choice probably the 305 with the CNC chamber option for your stated goals. The exhaust port is only raised 3/8 "
I posted the numbers on the 315's a day or two ago & the 305 w/ the CNC option will come very close to about .650 or so. Low & mid numbers are killer & not inflated.
Here's the post:
web page (http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=4;t=020742;p=2)

The Air Gap would be my choice for an intake agaain for your stated goals but if you wanted to stay with a single plane the Vic Jr works very well.
Over 500 ft lbs from about 2900 on (peak was 610 @ 45-4600) with a little more cam & less compression in a 489. ;)
I've got all the specs on the engine if you want them but it's very close to what you are doing.

Cam looks pretty good, I'd have put a little more in but you have it & it will be very streetable, actually should be pretty mild in a 496.

If you email me I can probably save you a few dollars on the AFR's or Brodix if you want a smaller port & the lifters ;)

Hey Mike, thanks for responding. From what I've read so far it looks like AFR's are the way to go. The cam is the one already in the engine. Do the solid roller cams require replacement? (have run it for 4 years and about 10,000 miles) I will email you on the parts I may need. Nothing is set in stone yet, just gathering info. It is too easy to try the wrong parts and very hard to pick the right combo...

Originally posted by 69bigblock:
Hey Mike, thanks for responding. From what I've read so far it looks like AFR's are the way to go. The cam is the one already in the engine. Do the solid roller cams require replacement? (have run it for 4 years and about 10,000 miles) I will email you on the parts I may need. Nothing is set in stone yet, just gathering info. It is too easy to try the wrong parts and very hard to pick the right combo... =
You don't need to replace the cam unless it looks ugly when you inspect it.
But,,,,always a but huh :D
Most -8 comps are on a cast core which is something I do not run.
The -8 stuff seems to hold up ok on hyd stuff but I haven't had the best of luck with cast solids.
You cannot normally run over about 450lbs of spring without hurting them which seems to work on the lobes designed for this amount of spring ok most of the time.
Problem I have with this is Comp is testing a specific lobe, lifter, pushrod, rocker, valve & spring combination & it works,, according to them.
If you deviate from these parts with the recommended spring you may have problems.
It only takes a few times of bouncing the lifter off the lobe to beat the crap out of your cam & lifters.

Strange thing is, when I had the 254/260 lobes custom ground on a billet Comp recommended a spring (991) that ended up like 225 & almost 600 open???

Anyway, I don't run rollers with less than about 200/500 & usually prefer about 225/550 & up depending on the cam & you should not do this except on a billet.
Do you know what spring & lifter you are using? It appears to be working very well at 4 years.
I am going to assume it is the 819 lifter & not the Endurex.

69,
Looks like a good combo.
For NA use I think a RPM would be better but in your case I would use the Vic Jr as Mike suggested.

I would definitely up the compression ratio to near 11-1 with an aluminum head if not a little over 11-1.

Let the motor pull the car not the gear, those cubes will pull the car with a 3.73 gear...

And less converter than "normal".

I'd stay with the current cam if it is billet and OK. Isky or Crower SD lifters.

On machine work..
I'm just up the road from ya in Denton. I take my stuff to a guy in Oklahoma. About 2 hrs from Dallas up I-75.

I've used local racing shops. etc.. not again.

I've heard good stuff about Kim Barr, Hohn's (sp?), and a couple of others locally but the guy I go to has been doing it for decades, he is the only one who will wokr on your stuff. No employees, no guesswork.

He does excellent work, and the pirce for race quality work is about what run of the mill work costs around here..

Grice's Machine in Durant, OK. I've known the guy for a long time.

Self's Racing is also in Durant. Glen Self was the NHRA record holder in the early 80's with a Chev inline 6 against V8's....

grice would be a little cheaper, not as facny of a shop but it is who I use, Self has the showroom looking shop, cost more, has 5 sons who also work on the stuff, but I wouldn't be afraid to drop my stuff off there, maybe jsut afraid of the bill when I went to pick it up smile.gif

Actually either would be cheaper than local comparable shops probably.

Good luck.

I'll be making a run to Grice's middle of the week.

Hi Jake, thanks for your input. The vic/rpm decision is a difficult one. There are 10 times as many bad shops as there are good ones.

So far the changes look to be:

1)Everything magnifluxed and put a new set of rod bolts in along with new bearings and rings of course.

2)RPM intake w/fogger lines installed.

3)AFR 305/315 with the CNC chamber +.8 or so cr

4)Keep cam if good otherwise?

5)Isky lifters, Pro magnum rockers

6)3.73/3/90 gear change

7)Rebuild tranny with less stall

Cost estimate anyone? Brother can you spare a grand?

Frank,

Sounds like you have a good plan put together.

On the machine work several of my friends have used Kim Barr with good success. I've also heard Max Long at Wharehouse Auto in Irving does good work, but I don't know anyone that has used him. There is always Reher-Morrison as well. I figured their prices would be outrageous given their name and reputation, but they were right in line with most good shops when I checked with them on the machine work for my 445 SBC. They are a good 1-1/2 hours away for you though.

A guy I work with recommends Grice's also. Seems to be very thorough from what he's told me.

If you are just going to have them do the magniflux and maybe hone the cylinders and do the rest yourself, I would probably just go with Kim Barr as he is in Garland. If you are going have someone assemble the whole deal you might do a little more research, talk to folks at the track, and talk to the various shops to see who you are most comfortable with.

I wouldn't even sweat rod bolts if you already have a ARP Waveloc or better.

The rod will fatique before the bolt unless your doing teardowns all the time...