mguidry629

iTrader: (6)

383 w/cast Eagle crank, so I don't want to go too extreme. Need to stay under 450-480fwhp. I have stock ported heads, but may upgrade in the future. 11.25CR. Car will be a weekend/strip car, but would like to keep streetability. I'm going with 3.73 gears and will get a stall based on the cam. So I need opinions on both.

As of now, I really like the comp's 280xfi grind. On comp's camquest, the torque curve looks awesome and peak hp is at 5500, so I wouldn't have to spin too high. But I'm really leaning towards a custom grind. I just want to get as much out of the stock heads as possible. I had the CC305 on my 383 and ran 13.0 with a lot of knock retard and street tires. I'm hoping to get closer to 12.0 or maybe creep into the high 11s.

I will be using my 1.52 sa comp rockers for now, but getting new springs, pushrods, etc.

So please let me hear your suggestions on cam, stall, springs, pushrods for my combination.

And I need cash to fund all this, so please go to the link in my sig and buy something, lol.

Gojira94

iTrader: (4)

Do you have flow numbers on the heads and did you plug them into Camquest, along with correct valve sizes, etc.? It'll make a lot of difference... also on 1.52 SAs your lift is .547/.541 which is still decent if you've got good bowl work, port velocity, 5-angle job on some lightweight valves. Though it won't make all the power it wants to because of the lift reduction. 1.6 Pro Mags and guideplates/ PRs will make it a lot happier when you can get to them in your budget.

I like that cam a lot for a mild 383...

96capricemgr

iTrader: (1)

You say "stock ported heads" like it is an automatic compromise.
If done right the stock heads with proper porting are a GREAT choice for most builds, probably safe to assume based on your post though that you halfassed it.
That crank is at SERIOUS risk for failure even on something this mild, search here and you can see the many pictures of what happens when folks cheap out and buy a Eagle cast crank.

Ignore Comp's simulations. Peak HP will be above that rpm, way above that, if the heads are vaguely decent probably a good 6-800rpm higher. Hell a stock LT1 peaks almost that high in the rpm range.

13.0 on street tires sounds OK till you understand that my heads/cam Caprice with the old 190cc head 226/234 cam 3400stall, 3.73s, slicks tools and jack in the trunk ran 12.7 on street tires immediatly upon arrival at the track after an over 2 hour drive to get there, I even have video. I would guestimate weight with the trunk full like that at at least 4350lbs.

You have gotten too far into this without any true understanding, you have already spent too much and gotten too little and the crank you have is FAR weaker than stock. I would not do anything till you have a backup plan for if that crank shatters.

Not what you wanted to hear but seeing as my Caprice when year round(in Wisconsin) daily drivable was faster than what you have and what you want, maybe I have the experience to comment. These days the car is too much to handle in the snow, but my last heads/cam setup was fine with the little less stall and gear, smaller TB all helping it apply power more gradually.

IMO at this point your money would be better spent replacing that crank and keeping the 305 cam. I am NOT a fan of the 305 cam but at this point it is not the biggest issue in the setup. So at this point I think it would be foolish to spend $500+ on a custom cam and springs.
I would also say the XFI 280 would be a better choice than the 305, but again I think you should focus your attention elsewhere first.

quik95lt1

iTrader: (7)

http://s322636171.e-shop.info/shop/a...26aid%3D156%26

buy this kit and run the 234/242 .575/.595 110LSA cam from AI

if you dont want to buy the whole kit run the same spring and retainer package that comes with that kit

as for stall run a 3600

defaultexistence

iTrader: (11)

it is inevitable padawan , we All must conform to the forged side of the crank force

henry172

iTrader: (2)

Go with a yank 3600 stall; that would be your best bet, I have a edge racing 3200 it is really nice and a couple $100 less. Like others have pointed out I would not trust that crank; I did not have the cash for a forged crank so I used the stock crank and built a 355 instead.

mguidry629

iTrader: (6)

That kit doesn't include springs and retainers, but I get the idea. They have another kit I think you are referring to. I can get parts discounted at my local engine parts, so I don't think I will be buying directly from AI, but I can get the same parts.

Everyone says Yank 3600 for every application on here. Comp recommends 2000-3000 stall for the 280xfi in a 383. My uncle/builder thinks a bigger stall will just slip more and lose HP threw the powertrain, so he wants me to stay with a stock size stall. I don't necessarily agree with that, but 3600 may be too much if I'm making power from 2000-5000 and shifting at 5500.

No flow numbers, but he's been porting heads for 20 years. When you say lift is .547/.541, are you referring to the 280xfi, because it's lift is 576/570 on a 1.5rr unless I'm missing something.

I understand the risk I'm taking with the crank. I could go into detail as to why I have to stick with the crank, but I'll spare us all the time. It has to do with my uncle doing my machine work for free and not wanting to abuse that.

I appreciate your input.

96capricemgr

iTrader: (1)

You are taking advise from folks who haven't learned much in DECADES and that is going to torpedo your build.

The XFI lobes all assume a 1.6 rocker.

LSWHO

iTrader: (1)

Op I find it funny that you ignore people that own and modify these cars PERSONALLY and instead think somebody with seemingly zero experience in lt1 cars spec anything for you.

If anything you should go with the general consensus of informed people.

3200 should not be recommended for an lt1. Unless it never sees the track. IMO a tracked lt1 should NEVER go below 3600 rpm. It's a waste of time. You'll realize bigger would have been better immediately.

I started with a 3000. I switched to a 3200 stall thinking I needed more when I was bolt on. I quickly realized I should have gone higher. ON A MILD BOLT ON CAR. (stall/LTs only)

mguidry629

iTrader: (6)

Thanks for clearing up the 1.6 for xfi lobes. Comp's website says it's on a "standard rocker ratio".

I would still like some opinions on cam specs, valve springs, stall, etc.

LSWHO

iTrader: (1)

Best advice I saw so far. If you don't want to go through ai find a simlar cam that you are willing to buy and post it up to get opinions.

96capricemgr

iTrader: (1)

Back when I was putting 20K miles a year on my Caprice I had a 2800 stall in it and some gearhead passengers mistook it for stock till I dropped the hammer. Converter technology has come a long ways in the last few decades and lockup means no slip at cruise. They have gotten a LOT more efficient too.

mguidry629

iTrader: (6)

Didn't see the two posts above until after I posted. I'm not ignoring anyone. I trust what most say on this site, especially when you read the same things over and over from the more experienced guys. I'm just trying to get advice and learn why, so I can explain why I want to do it my way. I'm trying to buy this stuff "I" want and get my uncle on board with it. But when he knows he's right and I'm new to this, how I am supposed to convince him he's wrong. No he doesn't deal with building combinations on the LT1 on a daily basis, but he physically builds motors, balances cranks, bores, decks, hones, valve jobs and does all machine work on a daily basis. He is good at that, but his customers are the ones that put the combinations together.

I guess the moral of the story is that a machinest doesn't necessarily know how to build a winning combination.

LSWHO

iTrader: (1)

Order a 3600+ stall and tell him it's a 3000.

mguidry629

iTrader: (6)

Now that's a good idea. Then order some $200 Crane springs and tell him I got a good deal on some used ones. I like where this is going. An actual solution to my problems.

henry172

iTrader: (2)

Here is why you should not run that cast crank
I would hate to have this happen.