I have a LB9 auto 89 IROC vert - peanut cam, 3:42 rear. I've got the car almost "finished." But I can't decide what to do next. I have a GM 94666492 cam, Magnaflow Y-pipe, and a healthy WC T5/clutch setup ready to go on with a custom tune planned as well.

What I can't decide is what to do (if anything) about the engine

1. KEEP existing LB9 with 120,000 miles (fresh valve springs and seals but one failing oil ring in cylinder 2 but I can cleanup plug every few months and all is good). Put cam and Y-pipe in, custom tune and call it a day- OR

2. For $1,000, I can pickup a 49,000 mile L98 roller (iron heads) verified good but original, put the cam and transmission in on "the bench" then drop it in. I could freshen up the valve springs and seals on the bench too but apparently they are all fine.

I won't ever put slicks on it or drag race it or autocross it but I do like to make smoke and break the rear loose on the 1-2 shift every now and then :-). I know the WC T5 is relatively fragile, but I think I can keep it safe from the 350. I do not put many miles on it.

Trying to keep costs low but always looking to kick up the fun factor. Would the cammed 350 really feel that much "whiz bang better" than the similarly cammed 305 with the T5 added in either case?

What WOULD YOU do?

 

I would get the L98, do all the stuff on the stand, swap over your valve springs and seals and drop it in

 

I'm with Scooter. 350 > 305 in just about every conceivable way. $1000 seems a bit pricey to me, though.

 

$1000 isn't too bad if it's ALL ORIGINAL, most especially, the heads & pistons; and if it's a F body one (not Vette). And even more so if it's "guaranteed", such as from a junkyard... although actually executing such a "guarantee" might be tough at best, since it's kinda hard to place an order for somebody to go out and wreck a similar car with similar mileage, on demand. It's not like buying a motor for a 10-yr-old Chevy truck or something, where there's BILLIONS of em available at all times.

Look inside the spark plug holes for flat-top pistons, and pop a valve cover off and verify that the heads are 083 casting. Don't bother if the heads are ANY other; or, get the #s and post them here and we'll easily be able to tell you if they'll work like you need.

I'd get new valve guide seals but maybe swap the springs over. Maybe put new valve cover and oil pan gaskets in it.

Now would be a good time to put in a cam if you want, something obviously that would be emissions-compliant on the original tune and wouldn't raise any suspicions at the smog station. Odds are very good that they will NEVER notice the 305 vs 350 difference, as that is entirely internal. Such a cam would be the Comp "501" grind https://www.summitracing.com/parts/cca-08-501-8 which will work with the existing L98 lifters (or the ones out of your 305) and all that. The springs would need to be set up carefully to avoid problems; an easy way to upgrade those but avoid any issues would be to use LS6 springs, Comp 787 retainers, and the Comp keepers that go with those retainers.

 

Tootie you been wanting more from that 305 for so long now that if all Sofa's concearns can bet met and you have the mean$ to do it....man I think you know the answer here!

 

You should go buy that L98 today. Yes it will be much better than the 305 and you will definitely tell the difference. I'm doing a similar swap myself.I bought a 70k no L98 and doing rings, bearings, seals, and cam swap also

 

Awesome help all. Many thanks. So, Sofa, can I use the cam I’m planning on putting in? Should I even put a cam in? I know the L98 has a much hotter cam than the peanut. So maybe the improvement would be much less? Especially considering the TPI is going to be that much more restrictive in the 350.

 

Why would you want to put the peanut cam in? I would either leave the L98 cam or replace the cam with 501 cam Sofa mentioned (or similar).

 

What cam do you have? Memory is pitiful... you know what "they" say, "they" say the 2nd thing you lose when you start getting old is your memory; problem is, I forgot what the 1st one was supposed to be...

 

Lol. I suspect I am indecisive but I can’t make up my mind.

I have the GM 94666492 ready to put in which has these specs:

from a previous thread

“Same cam as a Crane 2032 with a much cheaper price tag.
270/276 @ 0.004
214/220 @ .050
.452/.465" LIFT
112 LSA, 108 ICL”

 

That GM6492 cam should be a great upgrade I thought serious about buying one myself

 

Should be fine.

 

Just helped a member with tuning this cam. Not sure if he had spring bind but his head studs came out.
he was using swirl port heads . You might want to do screw in studs or pin the presses in studs. Check for bund the cams lift is close to max lift on a sbc head. Iirc .470 is max lift on a stock head.

 

My $.02. That crane 2032 cam is gutless in a 383. It was installed in my car when i bought it from the previous owner. It idled and drove like a stock cam. I am suspecting it will feel like stock in a 350, but more aggressive in a 305. I would look into better cams than the crane 2032 if you can help it. If you bought it already than i guess you could sell it or trade for another cam, or just run it.

 

In CA, you get used to accepting a certain dose of "gutless". Unless of course you're a Silicon Valley gazillionaire. which of course, I never was.

But, in 2019, if you want to redefine "gutless", try driving a bone stock L98. I got stuck with some Frod POS the other day that I thought elevated "gutless" to an unprecedented level; an "Eco Sport" or some such bog. What a smarmy steaming bucket of greasy green gooey last night's beer and pizza s***. I remembered all over again the brand-new LB9 and L98 cars I test-drove in the early 80s and … left on the lot.

 

Turns out I couldn’t verify the mileage of the motor with the possibility that it had 250,000 miles on it. So unless I find the right block and heads at a local machine shop- a remote but real possibility, I’ll be going with the little 305 from plan A.

And thanks Brian. I’ ll keep an an eye out for spring bind when I turn it over. I’m looking forward to the improvement with the cam, Y, and T5.

 

I just saw a rebuilt 5.7 vortech lower end forsale on offer up for 400 locally.

 

 

I would ABSOLUTELY NOT buy that motor for the situation at hand, which I am assuming, this is posted as an alternative to AN ENTIRE RUNNING one.

Even if "Vortec" was spelled right.

It's going to be the CHEEEEEEEEEEEPEST OF THE CHEEEEEEEEEEEEP in every way. One look at the pistons shows that they are WRONG: they are dished. It also looks like it has quite a bit of deck clearance. Overall, this is targeted at someone who has a fleet, and one of their junior employees kept driving it for a few days after the radiator popped, and now they need to get their van back on the road earning revenue. NOT a "performance" oriented, ATTENTION TO DETAIL, carefully executed, "a cut above" kind of build. Just altogether NOT the answer for someone who's looking for an "upgrade".

 

Zowee! Maybe I can "Ask" Lyana out (or even cut to the chase and "Make Offer") to discuss what makes her motor run!

 

Typical sales tactic that arouses suspicion.