Building a 355
02-07-2014, 12:31 PM
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Building a 355 I got a fresh 355. Flattop pistons. Stock crank. Block is a 2 bolt. Has 305 heads and a eld intake with a 600cfm eld carb. I need a good combo for my 355 in a $500-1500 budget. Im looking for a big cam combo. What kinda rockers? Intake? Heads? Any sugestions? I herd 305 heads on a long run will ruin my motor. My motor will be carbed in put in a 98 firebird convertable.
02-07-2014, 08:39 PM
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Is this a DD or just weekend cruiser? with the info you listed i'm guessing cast/hyperutectic pistons and a 2 bolt block is not going to handle a lot of power even if you have studs in the bottom end. Do not run the 305 heads
they have smaller intake valves 1.84 vs. 1.95 for stock 350 heads. With the 305 heads depending on the casting# for closed chamber design they will
give you no less than 11.1 comp. with the flat-tops. Use 350 heads, the vortec head is good with minor work. I ran 186 castings for years, these were off of 1969 to about 1972 models. Both of these heads would give you around 10 to 10.25 to 1 comp. Thats about max for iron heads and pump gas. We ran a comp cams .480" 230@.050", torquer II intake with 2" open spacer and 650 dbl. pumper, headers and made close to 425 hp. You need a good set of roller rockers and screwin studs with guide plates. Stock rockers want cut it. If your budget will allow you can get find aluminum heads at a decent price and make more power.
they have smaller intake valves 1.84 vs. 1.95 for stock 350 heads. With the 305 heads depending on the casting# for closed chamber design they will
give you no less than 11.1 comp. with the flat-tops. Use 350 heads, the vortec head is good with minor work. I ran 186 castings for years, these were off of 1969 to about 1972 models. Both of these heads would give you around 10 to 10.25 to 1 comp. Thats about max for iron heads and pump gas. We ran a comp cams .480" 230@.050", torquer II intake with 2" open spacer and 650 dbl. pumper, headers and made close to 425 hp. You need a good set of roller rockers and screwin studs with guide plates. Stock rockers want cut it. If your budget will allow you can get find aluminum heads at a decent price and make more power.
02-08-2014, 05:32 PM
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With stock crank and rods maybe 450 and have it live for awhile. I would use some good studs in the main caps and aftermarket rod bolts this will help add some insurance.
