this weekend we are replaceing our 350 with a 455. its a stock 455 with headers. what would be some good cheap things to start out with seeing as our engine is already apart. we dont have alot of cash but we know we are replaceing all the gaskets and cleaning the heads. if it dont cost too much we are going to get a valve job and possible port and polish done. and having all the ports gasket matched ( intake and head). and what is the power of a 70 455 not sure what it came out of just know the year.

 

Figure IF it's all stock and a 4bbl engine then it's factory rated at 10.25:1 compression. 365 HP/500FT LBS of torque.

If it's a 71 or later it will have the lower compression pistons (8.5:1).

 

Aaron, you have a PM, non-Olds related.

Look on the shelf between intake and water pump and tell us if it is an F or Fa block. That helps narrow down the year.

Find the machined pad at front left side of the engine. This shows a VIN derivative from the car it was originally installed in and indicates the exact year. A 1970 block should start with 30 (3= Oldsmobile, 0= 1970).

Then look at the heads. You will see a letter cast into them at the lower left corner, near the spark plug hole. This identifies the head. C, E, G/Ga and J are common, with the C and E being the overall best flowing. A 1970 block should have Es. J are low compression smogger heads that are OK but even fully ported/polished do not flow as well as stock Cs, and they tend to crack exhaust seats.

D and F are W30 heads. IMO suitable only for a numbers matching restoration because of their rarity and expense. H and K/Ka are uncommon, and A and B are 1965-66 425 heads which may not mate up well to 68-later cam and pushrod geometry.

Be aware there are big and small valve versions of the C and no good way to tell except measure the valves. Nothing external to indicate valve size.

If it's already apart I'd at least pull a main and rod bearing cap to see what shape the bearings are in. No point spending performance money on an engine that's going to grenade 'cause the bearings are worn.

A new oil pump would be good and a new timing chain/gears is a must. Check yer cam and valvetrain over good before you decide to reuse it.

Multi-angle valve job if you can afford it. Otherwise do the valve job to Toronado/442 factory specs.

g

 

Hey;If you are going to match port there is little expense but if you will be paying to have it done money is better spent elsewere. As rocketraider said oil pump,oil pump pick-up, timing components and clean everything.

 

I guess keeping it as cheap as possible depends on what the engine needs and what your needs are....Its rarely as simple as just cleaning it up...no point in wasting money on a port and polish if you dont take care of things like new pistons, cam, balancing etc...just my opinion cause I been there done that...

 

(move to big block section)