I have a pair of 083 heads off an 87 350. I was looking to swap my stock heads with those, add an LT1 cam, and possibly add roller rockers. Question is, will the stock TBI unit keep up with the fuel demand or will I need to upgrade that as well?

Thanks

 

The TB might keep up, might have to increase fuel pressure a bit nothing major. Your tune or chip won't keep up, you'll need to look into DIY tuning if you want to reach the full potential of that combo. You'll get about half the power when you swap the parts and the other half when you tune it. Just an educated guess.

 

I was waiting to order a chip for my current setup until I decided on this. I guess he could retune it for me tho. I am trying to do this at minimal cost. I've found a good LT1 cam for practically nothing and the machine shop will do the heads for $100. So would I just get a AFPR and fine tune it?

Also, does anyone think the swap isn't worth the effort and money?

This is just my project car so time is of no consequence. I am painting it right now, so that would be the next project after the 3.23s go in .

 

My deffinition of tuning doesn't involve mail order chips or a fuel pressure regulator by itself. It involves DIY chip burning. I wouldn't mess with the fuel pressure unless I was tuning chips. Some people have had luck with the mail order route, mostly with stock vehicles. The further from stock you get the less likely your going to get something thats worth your money. Just too many variables to explain over an e-mail or the phone.

If you have time to spare I suggest you start reading up on DIY prom tuning and start piddling around with it. For the price of your "custom" chip you can get an inexpensive burner and be on your way to tuning it yourself.

 

I think there is a how to on that on the site, isn't there? I'll do a as earch and see what I find. Thanks!

 

Yep there sure is, go to the tech article section and start with Taxion's intro to prom burning article, then step up to the stickies at the top of the page in the DIY prom board. Don't worry about the more advanced stuff like source code. If you have any questions feel free to ask me or post on the DIY prom board, Just make sure you you read traxion's article a few times, you won't pick it all up the first time through.

Just so you know you have the 746 ecm that uses the $61 mask.

 

I think those 083 heads will drop the compression pretty bad on your 305. You want the 081 heads.

 

well, crap. I'll double check the number but I am pretty sure they are 083 (87 TPI heads).

 

Let me throw these scenarios out to you.

The heads are attached to the 350. What if I swapped the 350 in and used the stock 305 TBI and intake. Can I use the 305 intake and TBI on the 350? Other than the obvious chip issues, what else would be different? Anything?

What if I just swap in the LT1 cam and keep the stock heads? What else should I do?

Would the stock heads support a ZZ4 cam? I have one of those too.

just talking thru some things, I have plenty of time to piddle with it.

 

If the 350 is in good shape go with that. Your intake along with everything else will bolt right up to it. The LT1 cam and 083 heads on the 350 would be a good start. You will need 350 injectors, ESC module and knock sensor though. It may also be a good time to replace the weak fuel pump with a Walbro unit.

 

the zz4 is going to be to big for those heads zz4 cam Lift: .474/.510
the 081 and the 083 can only take a Max of .480
the lt1 with 1.5 rocker should be perfect depending on the year of the cam you may find the specs here and see if you can run 1.6 if you would like.... other wise if you wanted to id do some port work slap in the lt1 cam do some tuning and im sure you should see 260 to 290 HP

http://www.fierolt1.com/lt1_camdata.htm

 

Needy- I've had my LO3 heads ported and polished, 3 angle valve job, new springs and currently have the stock rockers (along with the other mods in sig). Are you saying with the LT1 cam and roller rockers in my current setup I should expect that HP number or is that with the 350??? The cam is from a 93 Z28 70K miles-- edit: so I can go with 1.6 rockers??

Shifty- should I go ahead and upgrade the fuel pump even with a LT1 cam swap? Also, if I decide to stay with my current setup and swap the cams, should I go ahead and upgrade the injectors or are the stockers fine? If so, what should I look for?

Thanks for all the help.

 

well LT1 engines are rated at 275 so logicy one would think you wouldn't see much more over that + the lt1 heads flow much better then the 083 castings witch should be took into consideration, don't let me get your hopes up anything but the number should be close to that of the LT1s, i think that with the 1.6 on your 93 cam is pushing it, a safe limit should be .470" but shifty would know more about that i think then i do

 

If he is going to put the 083 heads on a 305 don't they need to be milled down to keep the compression up?

 

it looks to be he is useing the hole 350 and adding tbi

 

i thot you where using 083s?

 

A new fuel pump is a good idea no matter what engine you go with. The stockers are weak and cann't supply enough fuel at WOT. Some can but most can't. $100 will get you onw that will support more power than you could dream of. If you go with the 350 you will need larger injectors no matter what you do to the motor. If you keep the 305 and just go with the LT1 you should be able to get away with the stockers and some crafty tuning and pressure tweaks. Your tuning will tell you if you are starving for fuel of not. Most heads and LT1 cammed LO3's need at least larger fuel pump. It certainly won't hurt you if you step up to larger injectors and tune around them.

 

what fuel pump would you reccomend, i am doing the LT1 cam in a 350cid w/ 083's as well, so im going to assume i need that too...

 

I'd go for a Walbro 190. Buy it Here

 

sweet, i think i might pick one of those up... now, headers and a tune are all i need... freakin sweet!!