81blazerk5

Hi everyone, ive got a 94 b body lt1 and 4l60e swapped into my 81 blazer. I left if stock but now want to change some stuff, im looking at comp cams 230 236 cam and a set of springs. Ive already done the 1.6 rockers. Is that cam going to be too much for almost daily use then again i dont want to leave any room on the table. Best 1/4 so far is 15.0 at 90mph, with 4.10s. What else should i change while i swap the cam, ie water pump. I have spent alot of time looking into cam choice but i would like to know how they are to drive. Thanks

96capricemgr

iTrader: (1)

That would be a really bad choice.
Can rpm ranges from all the catalog companies are 6-800rpm lower than reality, I turn less duration than that right to 7000rpm peaking about 6400rpm.

The b-body heads you probably want to limit to about .535 lift unless you double check retainer to seal clearance.

Give us more info on supporting mods. Tire height, gearing.

In a 4300lbs with driver Caprice with 27-28" tires 3.42 2800stall are bare minimums even before say a 208/221 duration can. Taller tires, more weight and gearing requirement goes up, more duration stall requirement goes up and catalog crap like TCI should be avoided in favor of Yank, Vigilante, Circle D, Edge......

bufmatmuslepants

iTrader: (3)

81 fullsize blazer? 15.0 at 90 isn't freakin bad considering your pushing 5000lbs down the track. For that much weight, you need something with alot of bottom end power, not a high revving cam. Something like the crane 227, or get a custom one ground by AI or LE or TFS or someone else who knows lt1s. Comp and the other big names didn't put much R&D into the lt1 since the ls1 came out so quick after, but there are some nice little cams that will help you move. You probably have 3.08 gears since 81 would have had a th350.

bowtienut

iTrader: (1)

For that vehicle and the times you're running, you really shouldn't be messing with a cam at all at this point. I pushed that same cam to 12.3's in a B-body. Gearing, torque converter, and traction gets you there
Your torque converter idea is a good one. Since it's a heavy vehicle, I'd go with either a Yank Truck Thruster 3000 if you do any towing, or a SS3200 if you don't. With a heavy vehicle and especially if you tow, stay away from the small diameter non-billet units; the lockup clutch is not up to the task in those.

I agree 15.0 @ 90 IS respectable for that tank
The most I'd do to the engine at this point is some better valve springs and 1.6 rockers so it will make power to at least 5500 rpm. The springs on the iron head LT1's are crap compared to the stock Al head springs.

81blazerk5

The truck weighs 4300 with me in it so it's not super heavy. I have already swapped the gears to 4.10s with an eaton, done 1.6 rockers and long tubes. The torque converter is a big problem, she just coasts off the line. I have a 3200 circle d about to go into another project with an ls so I want to drive that around before I choose how high I want to drive around daily. A friend of mine has a comp cams 218 in a tbi with a speed and there's almost no lump or loss of drivability. My goal is to break into the 13's. Is .535 max lift to the piston valve clearance.

96capricemgr

iTrader: (1)

Lift has little to do with PTV clearance, valve timing does. That said .600 lift is pretty common on stock short block LT1s with milled heads and thin head gasket.
The .535 as I said is a spring retainer to seal clearance issue.
Thank you for posting weight, people often forget how empty and lite old stuff is.