When looking at replacing an engine in a 75 Corvette, what is there to look for? I know that there are different generation engine blocks but will any 350 work or are there certain things different about the blocks that will affect whether or not they can be put in without any mods to the car?

 

Why dont you have original engine rebuilt? Everything will work correctly together.

 

Or get a crate motor. If you're not planning on doing some crazy type of build, or going original, you can't beat GMPP crate motor.

 

There are 86 and earlier and '87 up blocks basically...

86/earlier blocks will have
1. 2 piece main seal
2. Provision for mechanical fuel pump
3. Block machined for Flat Tappet Lifters

87/newer will have

1. 1 piece main seal
2. NO provision for a mechanical fuel pump
3. Block Machined for ROLLER LIFTERS

You can make 350 to 400hp very easily and inexpensively
with stock heads and either block... and up to 450hp with $600 aftermarket heads.

I have some combos you can use for a guarateed 350-370hp that
will save you $1500 over the guys who bought ZZ4's.

 

I am pretty sure any Gen 1 small block has provisions for fuel pump, newer big blocks, Gen IV and up, do not.

 

Nope... the Roller Cam blocks are Fuel Injection blocks and were
made without a provision for a mechanical fuel pump as EFI systems use an electric fuel pump.

You can still use carburetors on a Roller Cam block but you must
use an Electric Fuel pump..

Here is the '87 up shortblock at Pace... no mechanical fuel pump
is in the description:
http://paceperformance.com/index.asp...&ProdID=184534

 

http://store.summitracing.com/partde...5&autoview=sku

This is a one piece rean main seal block, what is the hole on the front right side for in the picture?

 

ZLX is showing a block that is used for truck applications with EFI, this is the exception, and not the rule.
The price of rebuilding adds up quickly. If you want to keep an original appearence, and are not concerned with # matching, consider GMPP 12499529 or 10067353, paint it chevy orange, and all your parts will bolt right on. Then take your original block, put it on a $30 engine stand and have it for future. Nobody knows if original motors will ever mean anything in the low compression C-3s, but you will have yours, untouhed.
If you are not looking for an original look, the GMPP 350/330 crate motor , part # 12486041, is availble base, deluxe or complete. Contrary to ZLX, this is a one piece rear seal, has provisions for roller cam and a mechanical fuel pump. This motor will appear slightly different than your 1975 as it will have center bolt valve covers and vortec style intake. Many agree that the vortec head is a steal at the price, and flows as well as some aftermarket aluminum heads.The head is limited to about .480 of lift, but can be machined or changed to a "beehive" type spring without removing the head. This will increase lift to about .525. Changing this motor to a complete roller cam is about $1,000. That would include cam, roller lifters, roller rockers and springs.
http://www.carcraft.com/techarticles...ine/index.html
http://www.carcraft.com/techarticles...ech/index.html
Here are a couple of good articles, do a google search for vortec, vortec build up, etc. These are just my opionions, hope they might help.
Good luck

 

I found a motor locally that is supposedly a 97 and later 5.7L vortec 4 bolt main engine with the vortec heads. It has the 10243880 block casting number, is this a good engine to build upon? What type of crank, rods, pistons, etc. does it have a will it work in a 75?

 

That is what we did. Then if you want to jack it up a little you have those options also. Plan on this too. Who ever helps you remove the engine not being available when it is time to replace it!!! Label/tag everything you dis-connect, everything you touch, and take a blue million pictures of everything as you take it apart. Make sure the engine
hoist does not start leaking fluild about 6 inches from getting the engine out of the car. Then you will get very frustrated when you have to let the air out of the tires just for enough clearance to get it out. If it has duct tape over the hole where you fill it up, that's a Sign!

I checked the price of a crate engine a few weeks ago. Warranty is the best thing about that. The regular person going in to get the crate motor would be around $3,000 ( valve covers down). If you know someone you can get it cheaper. That with you installing it. I think my buddy told me about $3,500 them installing it. Check the price,with the money we spent, and work involved. If you are happy with a stock motor and a good warranty that is the better deal. If you trust the mechanic.

Have a Great day,
Ray/aka/Pa

 

What else can you tell us about it? What does the seller say it is coming from? How many miles, what is included, how many $$$$? The motors with the vortec heads are pretty much a replacement truck motor, which would not have a provision for a fuel pump, and the 350/330 hp crate motor, which is an excellant motor.

 

This is all I know about it. I am kind of skeptical about it since it is being sold as is and don't know about the condition of the block and components.

http://cgi.ebay.com/ebaymotors/Parts...1%7C240%3A1318

 

From the picture, I would say this motor has a roller cam because of the "hold down spider" for the roller lifters. I am pretty sure the roller cam on ly cam in truck motors, which could mean it does not have a fuel pump provision. Any help guys?
I tend to agree with you, this could be a decent deal, or a bunch of problems, no idea of miles, use or even if motor runs.
What is your goal with the motor swap? What is your budget? Is your car an automatic or a four speed?
I put a GMPP 350/330 in a Nova about 4 yrs ago, I think I had about $5,000 into it. That was everything brand new, starter, alternator, clutch, exhaust, belts, hoses, etc.

 

Nope, The L05 and L98 shortblocks are essentially the same.
NIETHER has a mechanical fuel pump provision.

NO MECHANICAL FUEL PUMP Provision ON THESE L05/L98 350's
used in these cars.

1. Chevrolet Caprice
2. Chevrolet Corvette L98
3. Pontiac Firebird
4. Chevrolet Camaro
5. Buick Roadmaster
6. Cadillac Fleetwood Brougham

The exception to the rule would be a mechancial fuel pump on
a Roller Cam/1 piece block.

PICTURES are often stock pictures of 350's.. not nessasarily
the product you are getting. Always look at the description...

LO5/L98 Shortblock:
http://paceperformance.com/index.asp...D&ProdID=42913

 

ZLX,
You are looking at one particular motor. Let me understand you, you are saying that any motor with a one piece rear seal, and roller cam provisions, will not have a fuel pump provision....
http://paceperformance.com/index.asp...&ProdID=131297

then why in the heck is pace giving you a fuel pump to put on this roller motor with a one piece rear seal?
You are jerking me, right? Why would anybody use a two bolt main block that you are referring to?
BTW, I still need to figure out what that thing is on the side of my 350/330 motor that has a fuel line into it, then goes to the carb.

Again, you are joking, what was the last crate motor you bought, and what year Vette do you have now?

 

So if a motor does not have a mechanical fuel pump provision, can it be machined to have one. I noticed that in the pics of the engine block that it has what appears to be a place for a mechanical fuel pump. I know that a lot of motors use a block off plate there but if a motor has an electric fuel pump, the block still has a place where a mechanical pump goes. What machining is required to make a mechanical pump work on a motor that used an electric pump?

 

Absolutely not... I have posted 2 DIFFERENT links 2 different motors.

Link 1- L31 Vortec Shortblock
Link 2- L05/L98 Shortblock

No GM car or Truck since 1990 has been made with a mechanical
fuel pump provision.

In 1987 when roller cams were introduced til 1989... 2 years
GM made blocks with both roller cam and mechanical fuel pump
provision.

The last L31 was in 2000 in GM Full Size Vans...
1990 to 2000... 10 years

2 years vs. 10 years... the majority of Roller Blocks/1 piece
Rear Mains are Electric Fuel pump only..... no mechanical fuel
pump provision.

Your motor may have been built on a leftover production block
of 87-89 vintage.
If you can find a part number for a Roller Block with Mechanical
Fuel Pump provisions currently for sale from a GM dealer please
post that part number and the dealer here.

 

Yep,

http://paceperformance.com/index.asp...&ProdID=131297
What is this?
And you haven't answered the question, "What was the last crate motor you bought?"

BTW, this is the second time I posted this,. You can buy a GMPP motor with roller cam and a mechanical fuel pump, maybe current production vehicles don't offer them. I am really not looking for a motor from a Caprice.
Please read the PacePerformance ad, I have bought a motor from them, have you? It is for sale, it has a one piece real seal, it has roller cam and has a mechanical fiuel pump, what can't you understand?
I guess if you are going to a junk yard to buy a block, 1987 and up will not have a fuel pump, GMPP offers them.......I don't buy from junk yards
also, this is the second time I posted a link to a motor , PEACE

Not only did I post part # and dealer, also a link,

 

http://forums.corvetteforum.com/c3-t...-question.html

 

My best guess to this situation is that most GM blocks are cast with the mechanical fuel pump connection on the block. My 93 truck has where a mechanical fuel pump would go but it is blocked off. My truck is TBI. I am betting that the only difference in the blocks is whether or not it has been machined to allow for the fuel pump rod on the electric fuel pump applications. On the carb. applications, it has. If the block is a good one, why mess with how it is cast when you can use it for both applications. Just my 2 cents and I am sure that someone can correct me if I am wrong.