Stupid question by stupid guy
- Thread starter hdpearson13
- Start date
- Status
The 2 bolt main 350 was the lower line 350, usually with a 2 barrel carb. The 4 bolt mains were in trucks and heavier duty/high performance versions in cars with 4 barrel carbs. These would include RPO's: LT-1. L-48, L-98, L-82 and LM-1( I think...). The L-48 was the first 4 barrel 350 and was rated at 300 or 290 hp, depending on weather or not the car was an SS. It came with 10.25:1 compression, a Quadrajet and 1.94 heads. It was used in everything from Novas to Camaros to Chevelles to Impalas. It was first available in the 1967 Camaro, the first car to get a 350. Other models got it in 1968. The LT-1 ( Not the LT1!) was available in the 1970 Z-28 and Corvette with 11:1 compression, solid cam, high rise aluminum intake, 2.02 heads, Holley 780, etc. It made 370hp in the Corvette and 360 in the Z-28. It was also used in COPO Novas sold by dealers like Yenko. The L-98 is the Vette TPI 350 used in mid 80's Vettes with around 250 hp. The L-82 is the 350 used in late 70's Z-28's and Vettes with 2.02 heads, hydraulic cam, Quadrajet and HEI. I don't remember what it made for power, probably 220hp. The LM-1 is the lamest 4 barrel 350 ever made, only putting out 155hp! It came in Camaros, Novas, Chevelles and Impalas in the mid 70's. Advertised compression was only 8.5:1 and the cam was laughably small. The 2 barrel 350 of those years made 130-140hp.
The 2 bolt 350 is not a bad engine, and some builders prefer it over a 4 bolt block. This is because of the thicker main webs as compared to the 4 bolt engine that can be drilled and tapped for much stronger splayed 4 bolt caps, such as those sold by Milodon. I run a 2 bolt 355 in my car with around 350 hp and it has never had a bottom end problem. Unless you plan on racing the car or making more than 500hp the 2 bolt block with a good set of main studs will serve you just fine.A Small Block Chevy is a VERY sturdy engine from the factory and can take a lot of abuse. It has few known serious flaws until you make a lot of power, and parts are very cheap.
A crate engine is just that, an engine you order and it comes in a crate. There are crate 355's which are worse than stock rebuilds at the local parts store with dished pistons and no quench with any head you can use, and there are nasty race motors you can mail order that are crate engines. There are also GM crate engines which have all new parts and have never been installed in a vehicle.
You can build a 355 with a simple .030 overbore on a stock junkyard block, but expect to also need to have it hot tanked, decked and line honed and have the money budgeted for those possibilities in case the block needs it. You will also need to have the rods assembled to the pistons by a machine shop as well as having the cam bearings installed. Then you would need to consider having the rotating assembly balanced if anything significantly deviates from the weight of the component it replaces. You could save money building your own engine or you could waste money if you do it wrong. For my money, I used a simple rebuilt long block that I got from my local machine shop, built to my specs with a cast crank, cast flat top pistons, good rings, double roller timing chain, Z-28 oil pump and World Products S/R Torquer heads and a cam of my choosing. It's not sexy, but it gets the job done as I planned the engine to be used in a pizza delivery car. Low end torque over Horsepower.I spent roughly $1700 on the long block 10 years ago and could probably do a little better for similar money today.
A 383 Requires different parts depending on what you want. If you want to rev higher, you will need longer rods, such as the 5.7 in rods off a non 400 Small Block Chevy, or aftermarket 6 inch rods. Both of them would require non stock pistons to accommodate the shorter compression height. You can use stock 400 rods, which are 5.565 in long, but they do limit you to less than 6,000RPM. You will also need to get a 400 balancer and flywheel/flexplate then have the whole rotating assembly balanced. Remember that a 400 uses a unique flywheel because it is externally balanced unlike all of the other Small Block Chevys. Same goes for the balancer.You may also need to clearance the bottoms of the bores so that the rods do not hit them. While the 383 usually would not need it, some stroker combinations sometimes require small base circle cams and their attending valvetrain pieces.
The 2 bolt 350 is not a bad engine, and some builders prefer it over a 4 bolt block. This is because of the thicker main webs as compared to the 4 bolt engine that can be drilled and tapped for much stronger splayed 4 bolt caps, such as those sold by Milodon. I run a 2 bolt 355 in my car with around 350 hp and it has never had a bottom end problem. Unless you plan on racing the car or making more than 500hp the 2 bolt block with a good set of main studs will serve you just fine.A Small Block Chevy is a VERY sturdy engine from the factory and can take a lot of abuse. It has few known serious flaws until you make a lot of power, and parts are very cheap.
A crate engine is just that, an engine you order and it comes in a crate. There are crate 355's which are worse than stock rebuilds at the local parts store with dished pistons and no quench with any head you can use, and there are nasty race motors you can mail order that are crate engines. There are also GM crate engines which have all new parts and have never been installed in a vehicle.
You can build a 355 with a simple .030 overbore on a stock junkyard block, but expect to also need to have it hot tanked, decked and line honed and have the money budgeted for those possibilities in case the block needs it. You will also need to have the rods assembled to the pistons by a machine shop as well as having the cam bearings installed. Then you would need to consider having the rotating assembly balanced if anything significantly deviates from the weight of the component it replaces. You could save money building your own engine or you could waste money if you do it wrong. For my money, I used a simple rebuilt long block that I got from my local machine shop, built to my specs with a cast crank, cast flat top pistons, good rings, double roller timing chain, Z-28 oil pump and World Products S/R Torquer heads and a cam of my choosing. It's not sexy, but it gets the job done as I planned the engine to be used in a pizza delivery car. Low end torque over Horsepower.I spent roughly $1700 on the long block 10 years ago and could probably do a little better for similar money today.
A 383 Requires different parts depending on what you want. If you want to rev higher, you will need longer rods, such as the 5.7 in rods off a non 400 Small Block Chevy, or aftermarket 6 inch rods. Both of them would require non stock pistons to accommodate the shorter compression height. You can use stock 400 rods, which are 5.565 in long, but they do limit you to less than 6,000RPM. You will also need to get a 400 balancer and flywheel/flexplate then have the whole rotating assembly balanced. Remember that a 400 uses a unique flywheel because it is externally balanced unlike all of the other Small Block Chevys. Same goes for the balancer.You may also need to clearance the bottoms of the bores so that the rods do not hit them. While the 383 usually would not need it, some stroker combinations sometimes require small base circle cams and their attending valvetrain pieces.
Thank you for the detailed message helps out alot now the last question would be is would i have to take my engine out to build a 355 and if i choose to go with just a 350 how much can i get out of it with out pull engine out. mostly what can i expect to get with bolt ons I would like to have a low 12s el camino whats it going to take to get there. I have a 350 the previous owner says its got between 230 and 275 horses other than the crate 350 and holley 650(which i beleive hesaid came with the crate) its all stock with th350 trans and i aint sure of the rear end but i know its a ten bolt. how can i get that to 12s I plan on 2.5 true duals and a fiberglass cowl hood and bumpers to save wait and i like the look. Its also lowered 3inches and has airshocks in the back but would like to keep the airshocks so i can haul my bike once or twice a year back up to PA(although I perfer the ride and hasnt ever been trailered) The guy doing the work on the exhaust and timing said he can raise the rear abit with some fabed spacers. also this may be a totally different question unrelated but have you everheard of anyone ever wetsanding grey rustouleum and the having someone clearcoat it. Thanks again
- Status
Similar threads
